Biochem MCQ 2019 Flashcards
In what organs Pentose Phosphate Pathway is a Major metabolic Pathway?
1)Mammary glands 2)Erythrocytes 3)Liver
Which of the following signaling molecules possess subunits in their structure:
- 1)PKC
- 2)PKA
- 3)Heterotrimeric G protein
- 4)Insulin receptor
- 5)EGF
2)PKA 3)Heterotrimeric G protein 4)Insulin receptor
Which of the following enzyme reactions is producing FADH2 and not NADH:
- 1)Alpha-ketoglutarate Dehydrogenase
- 2)Malate Dehydrogenase
- 3)Succinate Dehydrogenase
- 4)Isocitrate Dehydrogenase
3
Succinate Dehydrogenase produces FADH2.
Which of the following enzyme reactions is rate limiting step of the TCA cycle:
- 1)Alpha-ketoglutarate Dehydrogenase
- 2)Malate Dehydrogenase
- 3)Succinate Dehydrogenase
- 4)Isocitrate Dehydrogenase
4
Isocitrate Dehydrogenase is rate limiting step of the TCA cycle.
Substrates of Phosatidylserine Synthase 1 Enzyme:
- 1)Phosphatydilcholine
- 2)Phosphatydilethanolamine
- 3)CTP
- 4)Serine
- 5)ATP
- 6)DAG
- 7)CDP-DAG
1 , 4
Phosatidylserine Synthase 1:
Substrates: Phosphatydilcholine + Serine
Products: P-Serine + Choline
How many 2,3 BPG Molecules bind to the Tetramer Hemoglobin?
1
Phosphorylase Kinase:
1) Phosphorylates Glycogen Phosphorylase
2) Activates Glycogen Phosphorylase
3) Has Alpha, Beta, Gamma, Delta Subunits
4) Its Delta subunit is a Calmodulin.
5) Hydrolyzes the phosphate groups of Phosphorylase.
1 , 2 , 3 , 4
- Phosphorylase Kinase: Phosphorylates and Activates Glycogen Phosphorylase.
- Has Alpha, Beta, Gamma, Delta Subunits.
- Its Delta subunit is a Calmodulin.
Fructose Intolerance Cause?
Aldolase B deficiency
Why do you treat patients with tPA?
1) Protease that dissolves Fibrin.
2) Protease that converts Plasminogen to Plasmin.
3) it is no inhibited by plasma protease inhibitors.
4) Acts primarily in the location of Fibrin.
2 , 4
tPA is a protease that converts Plasminogen to Plasmin.
It acts primarily in the location of Fibrin.
What is the role of Hypertriacylglyceremia (HTG) in the development of Artherosclerosis?
HTG increases the shuttling of CETP (Cholesterol-ester transfer protein) HDL and VLDL with consequent formation of small dense LDL and Loss of HDL.
When Gla-domains are NOT formed in the blood coagulation proteins:
1) In Vit K - deficiency
2) In the presences of coumarin-derivatives
3) In the Liver disease when carboxylase cannot work
4) When in Hepatocyte, the epoxide reductase does not reduce vitamin K.
1 , 2 , 3 , 4
1) In Vit K - deficiency
2) In the presences of coumarin-derivatives
3) In the Liver disease when carboxylase cannot work
4) When in Hepatocyte, the epoxide reductase does not reduce vitamin K.
Unit of specific activity?
U/milligram
Lactose can be formed in a single step from:
1)Glucose 2)UDP-Galactose
In Partial Thromboplastin time (PTT) we learn about: 1)Factor VIII 2)Factor V 3)Factor X 4)Factor XII 5)Factor XI
1 , 2 , 3 , 4 , 5 Factor VIII, Factor XII, Factor XI -Belong to Intrinsic Pathway . Factor V and Factor X Belong to Common
True for Cori Cycle: 1) Liver takes up Lactate from Blood Circulation 2) Our body produces Lactate under resting conditions 3) Requires Energy 4) Links to types of tissues through the Circulation
1, 2 ,3, 4 1) Liver takes up Lactate from Blood Circulation 2) Our body produces Lactate under resting conditions 3) Requires Energy 4) Links to types of tissues through the Circulation
True for the formation of Malonyl-CoA: 1)Catalyzed by Citrate Lyase 2)Co-factor is Biotin 3)Negative feedback regulation by Palmitoyl-CoA 4)Regulated by Insulin and Glucagon 5)Requires ATP andBicarbonate
2 , 3 , 4 , 5 2)Co-factor is Biotin 3)Negative feedback regulation by Palmitoyl-CoA 4)Regulated by Insulin and Glucagon 5)Requires ATP andBicarbonate
Per Os administration of Uridine is a choice of treatment in case of: 1)UMP Synthase deficiency. 2)Orinithine transcarbamoylase deficiency. 3)Gout if allopurinol treatment causes orotic aciduria. 4)Solid tumers during 6-aza-uridine treatment.
1 , 2 , 3 , 4 -UMP Synthase deficiency. -Orinithine transcarbamoylase deficiency. -Gout if allopurinol treatment causes orotic aciduria. -Solid tumers during 6-aza-uridine treatment.
Aldolase B: 1)Cleaves F1,6BP 2)Cleaves F1P 3)Deficiency causes Essential Fructosuria 4)Deficiency causes Hereditary Fructose Intolerance 5)Symptoms of the deficiency are Hypoglycemia and Hyperuricemia.
1 , 2 , 4 , 5 Aldolase B cleaves mainly F1P. Deficiency causes Hereditary Fructose Intolerance and its Symptoms are Hypoglycemia and Hyperuricemia.
The binding of oxygen to Myoglobin relationship curve looks: 1)Sigmoidal 2)Linear - Positive 3)Linear - Negative 4)Hyperbolic
4 Hyperbolic
What is the “Induced fit” Concept: 1)Enzyme substrate binding induces an increase in the reaction entropy, therby catalyzing the reaction. 2)When a substrate binds to an enzyme the latter induces water loss. 3)Substrate binding may induce a Conformational change in the enzyme leading to better orientation of their functional groups 4)Enzyme specificity is induced by Substrate-Enzyme complex formation
3 Substrate binding may induce a Conformational change in the enzyme leading to better orientation of their functional groups
Which of the following lipoproteins doesn’t contain TAGs: 1)HDL3 2)HDL2 3)VLDL 4)Chylomicron
1) HDL3 HDL-Two ConTains TAGs
Choose the WRONG statement for Rynodine receptor: 1)its a Calcium channel 2)Has 4 subunits 3)It is the largest ion channel 4)Regulated by calmodulin 5)Same isoform for Heart and Skeletal Muscle
5 is Wrong! RYR1 - Skeletal Muscle RYR2 - Cardiac Muscle
Function of ABCA1 Transporter:
Pumps out cholesterol from extrahepatic tissue (to HDL)
True for the selectivity of Ion channel: 1)They can discriminate between identically charged ions. 2)They can only discriminate between Cations and Anions. 3)in Ca free media Ca channels become permeable for Na 4)Conserved P-loop Sequences determine selectivity of K, Na and Ca channels 5)Some ion channels are non-Selective.
1 , 3 , 4 , 5 -They can discriminate between identically charged ions. -In Ca free media Ca channels become permeable for Na -Conserved P-loop Sequences determine selectivity of K, Na and Ca channels -Some ion channels are non-Selective.
Open Probability is: 1)Total time spent open 2)Total observation time 3)Total time spent open/Total observation time 4)Total observation time/Total time spent open
3 Open Probability is:Total time spent open/Total observation time.
Which are True: 1)Glycolysis takes part in all humen cells. 2)the presence of oxygen is necessary for glycolysis 3)Pasteur effect is the phenomenon by which oxygen indirectly induces glycolysis 4)In mitochondrium containing cells end product of glycolysis is pyruvate 5)RBCs are capable of producing 4 mol of ATP from 1 mol of glucose.
1 , 4 Glycolysis takes part in all humen cells and In mitochondrium containing cells end product of glycolysis is pyruvate.
The induction of which proteins causes a decrease in the number of LDL receptors: 1)SRE 2)SREBP 3)SCAP 4)INSIG 5)IDOL
4 , 5 INSIG and IDOL are decreasing the number of LDLR, when induced by Insulin pathway and LXR respectively.
Isoelectric Point Defenition:
The pH at which a particular molecule carries no net electrical charge or is electrically neutral in the statistical mean
Which is NOT an electron carrier: 1)NAD 2)FAD 3)Biotin 4)Ubiquinone
3 Biotin is actually a Carboxyl-group carrier.
Which enzyme is not involved in Heme biosynthesis: 1) Heme Oxygenase 2) Aminolevulinic acid -Synthase 3)Aminolevulinic acid dehydratase 4)Urophorphyrinogen III Synthase 5)Urophorphyrinogen III Co-Synthase
1) Heme Oxygenase It is part of the Breakdown pathway.
Choose the enzymes induced by the Liver in Long term Starvation: 1) Aminotransferase 2) Phosphgluconate Dehydrogenase 3)Phosphenolpyruvate Carboxykinase (PEPCK) 4) Pyruvate Dehydrogenase 5) Malic Enzyme
1 , 3 Aminotransferase and PEPCK
Amino acids that enter the citric acid cycle as Alpha-Ketoglutarate: 1)Pro 2)Arg 3)Glu 4)Cys 5)Phe
1, 2 , 3 Amino acids that enter the citric acid cycle as Alpha-Ketoglutarate: Pro, Arg, Glu as well as His which is not asked.
Amino Acid without chiral Center
Gly
ABCG5 Function?
Pumps Cholesterol to Billiary Capillaries
Synthesized in the Zona Fasciculata of Adrenal Cortex: 1) Angiotensin II 2) Corticosterone 3) Cortisol 4) Angiotensinogen 5) Androstenedione
2 , 3 Corticosterone and Cortisol
Thrombomodulin effect on Blood coagulation: 1)Accelerates Activation of Protein C by thrombin 2)Inhibits fibrinogen conversion to Fibrin. 3)Activation of platelet by thrombin is inhibited by TM. 4)Inactivates Thrombin.
1 Thrombomodulin accelerates Activation of Protein C by thrombin. It changes Thrombin specificity and doesn’t act directly on none of the factors.
Which of the following conversions takes more than one step: 1)Alanine to Pyruvate 2)Glutamate to Alpha-Ketoglutarate 3)Aspartate to Oxaloacetate 4)Proline to Glutamate 5)Phenylalanine to Succinate
4 , 5 take more than one step. 1 ,2 ,3 are all transaminations carried by a single enzyme.
Major end product steroid hormone of Corpus Luteum:
Progesterone
What Statement is true for Insulin receptor substrate 1 (IRS1): 1)It is a Serine/Threonine kinase 2)It is a Phosphotyrosine docking protein 3)It binds to the Insulin receptor 4)Insulin receptor phosphorylates it on serine residues. 5)IP3 activates it.
2 It is a Phosphotyrosine docking protein.
True for the Dissolution of Fibrin: 1)Plasmin hydrolyzes the bonds between Fibrin monomers 2)Leukocytes participate in the process 3)Lys-Gln Isopeptide Cleavage occurs 4)Multiple peptide bonds within the fibrin monomers are hydrolyzed 5)A possible product is D-Dimer
2 , 4 , 5 2)Leukocytes participate in the process (Monocytes and Neutrophills) 4)Multiple peptide bonds within the fibrin monomers are hydrolyzed 5)A possible product is D-Dimer
Give at least 2 Cellular Elements Activating Glycogen Phosphorylase:
1) Calcium Signal 2) cAMP - PKA system 3) Phosphorylase Kinase
What is the dominant Electrophilic conjugation type in phase 2 Biotransformation:
Glutathione Conjugation
Type IIb (White) fibers : 1)has low glycogen content 2)has alot of capillaries 3)has low amount of mitochondria 4)Has high TAG content
3 Type IIb (White) fibers has low amount of mitochondria
Which of the following is NOT involved in Muscle contraction: 1)RYR 2)DHP 3)Nicotinic Ach Receptor 4)Beta receptor 5)L-type Calcium Channel
Beta receptors: They are part of the Sympathetic nervous system. All the rest take part in the Neuromuscular junction.
True for Transamination: 1) It is a reversible reaction 2) Co-factor for its enzymes is Pyridoxal Phosphate 3) First step is Ketoacid attaching to Lysine Residue of Enzyme forming a Schiff base 4)The Schiff base is in Tautomerism: equilibrium between Aldmine and Ketamine
All are true: 1) It is a reversible reaction 2) Co-factor for its enzymes is Pyridoxal Phosphate 3) First step is Ketoacid attaching to Lysine Residue of Enzyme forming a Schiff base 4)The Schiff base is in Tautomerism: equilibrium between Aldmine and Ketamine
Aminophenazone N-demythlation is catalyzed by: 1)Cytochrome Oxidaze 2)Catalase 3)CYP Isoenzyme 4)Superoxide dismutase 5)S-Adenosyl-Methionine
3 CYP Isoenzyme
Substrates of Phosatidylserine Synthase 2 Enzyme: 1)Phosphatydilcholine 2)Phosphatydilethanolamine 3)CTP 4)Serine 5)ATP 6)DAG 7)CDP-DAG
2 , 4 Phosatidylserine Synthase 2: Substrates: Phosphatydilethanolamine + Serine Products: P-Serine + Ethanolamine
Products of Oxidation of 3 moles of Glucose by the Pentose Phosphate Pathway?
3 Moles of Pentose 6 Moles of NADPH 3 Moles of CO2
What will increase in plasma due to the activity of Glucagon or ACTH?
Unesterified Fatty Acids
____ is a Primary bile acids formed by Hydroxylation, Side chain cleavage and Conjugation.
Taurocholic Acid is a Primary bile acids formed by Hydroxylation, Side chain cleavage and Conjugation.
Which enzyme will produce Dihydrotestosterone (DHEA) from Testosterone:
5-Alpha-Reductase
Inhibitor of Ribonucleotide Reductase: 1)Acyclovir 2)Methotrexate 3)araCTP 4)5-fuloro-deoxy-UMP
1 Acyclovir is a Reductase inhibitor
Roles of Nucleotides:
1) Hydrolysis of PP bound ATP to give energy. 2) DNA and RNA building blocks 3) act as Co-Enzymes 4) Second Messenger 5) Allosteric Effectors of Metabolic Processes
Orotic Aciduria is Caused by Deficiency of Enzymes in: 1)Epinephrine Synthesis 2)Purine Catabolism 3)Purine Synthesis 4)Pyrimidine Breakdown 5)Pyrimidine Synthesis (One Answer)
5) Pyrimidine Synthesis Bifunctional Enzyme UMP Synthase is Deficient. (Orotate Phosphorybosyl transferase + OMP Decarboxylase)
Choose the Substrates of PKA: 1)Glycogen Phosphorylase 2)Glycogen Synthase 3)Pyruvate Kinase 4)Hormone sensitive Lipase
ALL ! 1 , 2 , 3 , 4 -Glycogen Phosphorylase -Glycogen Synthase -Pyruvate Kinase -Hormone sensitive Lipase
True for 26S Proteasome: 1) Recognizes Misfolded proteins 2) Recognizes Ubiquitinated proteins 3) It is an ATPase 4) Beta subunits are the Catalytic ones 5) Alpha subunits are activators of Beta subunits
2 , 3 , 4 2) Recognizes Ubiquitinated proteins 3) It is an ATPase 4) Beta subunits are the Catalytic ones
Enzymatic Regulation of PDH Complex:
- PDH Kinase inactivates - PDH phosphatase activates
Which compound is substrate of Monoamine Oxidase: 1)Glutamate 2)Serotonin 3)Dopamine 4)Norepinephrine 5)Glutamine
2 , 3 , 4 Serotonin, Dopamine and NE are all metabolized by MAO.
Hyperuricemia will be the result of : 1)Glucose-6-phosphatase deficiency 2)HGPRT deficiency 3)Chemotherapy and Radiation therapy 4)PRPP-Amidotransferase Deficiency 5)Orotate-Phosphoribosyltransferase
1 , 2 , 3 Glucose-6-phosphatase and HGPRT deficiency. and Chemotherapy and Radiation therapy all cause an increase in Uric Acid in the Blood. (also in Mcardle disease)..
True for Enzymes: 1)Increase the equilibrium constant for a reaction, thus favoring the product formation 2)for effectivity they have to be equimolar to their substrates 3)They lower the activation energy for the reaction 4)They increase the stabillity of the product side. 5)Are never covalently attached to substrates or product.
3 They lower the activation energy for the reaction
Compounds or Enzymes of De-Novo Synthesis of AMP: 1)Ribose-5-Phosphate 2)Orotate 3)Aspartate carbamoyltransferase 4)Phosphrybosilformylgylcinamide synthetase 5)IMP
1 , 4 , 5 1)Ribose-5-Phosphate 4)Phosphrybosilformylgylcinamide synthetase 5)IMP (Orotate - Salvage , Asp carbamoyl… - Pyrimidines)
True for the results of Hypoxanthine-Guanine-Phosphoribosyl transferase deficiency:
1) Hypoxanthine is not converted to IMP
2) Hypoxanthine is not converted to GMP
3) Guanine is not converted to GMP
4) De-Novo Purine nucleotide synthesis is enhanced
5) Hyperuricemia develops
1 ,3 , 4 , 5 are True for HGPRT def . (Lesch nyhan): Hypoxanthine is not converted to IMP.
Guanine is not converted to GMP.
De-Novo Purine nucleotide synthesis is enhanced and Hyperuricemia develops.
Enzymes of Pyrimidine Salvage Reactions:
1) Thymine phosphribosyl transferase
2) Uridine-Cytidine Kinase
3) Deoxy-Cytidine Kinase
4) OMP Decarboxylase
1 , 2 , 3
1) Thymine phosphribosyl transferase
2) Uridine-Cytidine Kinase
3) Deoxy-Cytidine Kinase
Enzymes that catalyze the synthesis of long chain fatty acids in vertebrate cells (Pick one): 1)Are encoded in mitochondrial genes 2)Act as seven separate protein 3)Are part of a single polypeptide chain containing several distinct enzyme activities. 4)Are loclized in the mitochondrial matrix 5)None of the above
3 FA Synthase is a single polypeptide chain containing several distinct enzyme activities!
True for Kidney Cortex in starvation: 1)Glucagon activate Gluconeogenesis 2)Catecholamines activate Gluconeogenesis 3)Gluconeogenesis happens later than in Liver 4)There is high expression of Phosphofructokinase-1
2 , 3 Catecholamines activate Gluconeogenesis in the Kidney Cortex, this happens after a while in starvation - later than in Liver (pH dependent manner).
Synthesis of Tyrosine requires: 1)Phe 2)Phe Hydroxylase 3)Tetrahydrobiopterin 4)Dihydrobiopterin Reducatase 5)Alanine amino transferase activity in order to transform Phe to Phenyl-Pyruvate.
1 , 2 , 3 , 4 Synthesis of Tyrosine requires: Phe , Phe Hydroxylase, Tetrahydrobiopterin, Dihydrobiopterin Reductase.
Which of the following are Essential Amino Acids:
1) Ile
2) Ser
3) Cys
4) Phe
5) Trp
Isoleucine, Tryptophan and Phenylalanine are Essential amino acids.
How is Glycogen Phosphorylase is allosterically regulated:
1) Activated by AMP
2) Inhibited by ATP
3) Inhibited by AMP
4) Activated by ATP
5) Inhibited by Glucose
1 , 2 , 5
Glycogen Phosphorylase is allosterically Activated by AMP and allosterically Inhibited by Glucose and ATP.
Amino acids that are Ketogenic and Glucogenic:
1) Ile
2) His
3) Val
4) Arg
5) Tyr
1 , 5
Isoleucine and Tyrosine can form Ketone bodies as well as Glucose.
Glucagon regulation of Glycogen Storage (Pick One):
1) Simulates the Formation and Inhibits Breakdown 2)Inhibits the Formation and Stimulates the Breakdown 3)Inhibits Both Formation and Breakdown
4) Stimulates Both Formation and Breakdown
5) Stimulates Both Formation of Glycogen and Ketones
2
Glucagon inhibits the formation and stimulates the Breakdown
Amino acids with 4 carbons:
Asp , Asn ,Thr
Select the True statements:
1) Basic amino acids have net Positive charge at Neutral pH.
2) The Isoelectric point of basic amino acids is above 7 pH.
3) The Isoelectric point of the basic amino acids can be calculated as the average of their three pKa values.
4) Arg is a basic amino acid.
1 , 2 ,4 1)Basic amino acids have net Positive charge at Neutral pH. 2)The Isoelectric point of basic amino acids is above 7 pH. 4)Arg is a basic amino acid.
Are these two sentences true? Is there any connection? 1) Presynaptic Noradrenergic axon terminals retake up NE by Co-transport with Na. 2)NE re-uptake is decreased in Hypoxia.
Both sentences are True: Presynaptic Noradrenergic axon terminals retake up NE by Co-transport with Na (Secondary active transport). NE re-uptake is decreased in Hypoxia.(Na/K ATPase Low)
Glutamate is reduced to glutamic semialdehyde in the course of the formation of: 1)Proline 2)Ornithine 3)Glutamine 4)Glutathione 5)Gamma amino-butyrate
1 , 2 Glutamate is reduced to glutamic semialdehyde in the course of the formation of Proline and Ornithine.
In Fructose metabolism: 1)First step is a phosphorylation of fructose to F1P 2)First step is a phosphorylation of F1P to F1,6BP 3)First step is catalyzed by Fructokinase 4)All the same enzymes of glucose metabolism
1 , 3 First Fructose is converted to F1P by Fructokinase.
The accumulation of Citrate will: 1)Activate Glycolysis 2)Inhibit Glycolysis 3)No affect Glycolysis 4)Inhibit Gluconeogenesis
2 Inhibit Glycolysis
Which enzymes allows connection between the TCA cycle and Purine Nucleotide cycle: 1)Succinate Dehydrogenase 2)Citrate Synthase 3)PDH 4)Fumarase 5)Malate Dehydrogenase
4 , 5 - Malate Dehydrogenase and Fumarase: Fumarate coming from Adenylosuccinate lyase reaction can enter as malate to the mitochondrion and form oxlaoacetate.
True for HSL: 1)Activated in a cyclic AMP dependent manner. 2)Glucocorticoides induce transcription of the Enzyme. 3)Well-Fed induce transcription of the Enzyme. 4)Acts on the Surface of Endothelial Cells 5)Secreted by the Pancreas
1 , 2 are True for Hormone Sensitive Lipase. Activated in a cyclic AMP dependent manner. Glucocorticoides induce transcription of the Enzyme.
Which is the 30 Carbon Atoms Cholsterol precursor:
1) Isopernyl pyrophosphate
2) farnesyl pyrophosphate
3) Geranyl pyrophosphate
4) Squalene
5) Lithocholine
4
Squalene = 30 Carbons
Select the FALSE statement: 1)Arginine may be produced in the Kidney 2)Ornithine is synthesized from Glutamate 3)Nitrogen atoms in urea are derived from free ammonium ions and from Aspartate. 4)Urea can be produced in the Kidney.
4 is Wrong! Urea is produced in the Liver exclusively. only few parts of the urea cycle can occur in the kidney.
Pick the molecule that cannot go through the mitochondrial membrane: 1)Malate 2)Aspartate 3)Glutamate 4)Oxaloacetate
4 Oxaloacetate cannot go through the mitochondrial membrane.
UGT Enzyme location:
Endoplasmic Reticulum
Adenosine Deaminase reaction product:
Inosine
False for Nicotinic Receptors: 1)Activated by Ach 2)Linked to Myasthenia Gravis 3)Receptor Ion channel 4)Release Sodium only
4 Nicotinic AchR are releasing Na+ as well as K+
Which bases have an Amino-group in their structure: 1)Cytosine 2)Thymine 3)Uracil 4)Guanine 5)Adenine
1 , 4 , 5 -Cytosine -Guanine -Adenine
Cyclooxygenase:
1) Catalyses the conversion of Archidonate into Prostaglandins and Thromboxanes.
2) Inhibited by Aspirin
3) Hydrolyses the polyunsaturated fatty acid in SN2 position of Phopholipids
4) Is activated by indometacin
5) Inactivated in a Suicide Inhibition
1 , 2 , 5
Cyclooxygenases catalyse the conversion of Archidonate into Prostaglandins and Thromboxanes. Inhibited by Aspirin. Inactivated in a Suicide Inhibition
On which Lipoproteins ApoB-100 is found?
VLDL, IDL, LDL
Aspirin is used as a treatment for Myocardial infraction because:
It inhibits COX in Platelets.
Rate limiting step of Catecholamines synthesis: Enzyme, Co-factor, 3 Regulation ways
Tyrosine Hydroxylase Tetrahydrobiopterin regulated by: Ca++ and Phosphorylation which stimulate it. Norepinephrine cause negative feedback
Which is the unique enzyme expressed only in Zona Glomerulosa?
Aldosterone Synthase (18-Hydroxylase+Oxidase)
Pathways active in the Liver during Well-Fed state: 1)TAG Formation from FFA and Release of VLDL 2)Beta-Oxidation 3)Ketogenesis from Lactate 4)Lactate turning to Pyruvate and then to Acetyl-CoA 5)Lactate turning to Pyruvate and then to Oxaloacetate
1)TAG Formation from FFA and Release of VLDL 5)Lactate turning to Pyruvate and then to Oxaloacetate
Co-factors of Fatty Acid synthesis Pathway:
1)ACP 2)Biotin 3)NADPH
Typical Phase I reaction is : 1)Sulfatation 2)Glutathionation 3)Alklylation 4)Oxidation 5)Acetylation
4)Oxidation (or Hydroxylation) By Cytochrome P450 enzymes
Gilbert Syndrome is an unconjugated Hyperbillirubinemia just as ________ Syndrome.
Crigler - Nailar Syndrome
Correct ORDER for the enzymes of the De-Novo synthesis of Orotate: 1)Carbamoyl-Phosphate Synthase 2 2)Dihydroorotase 3)Asp transcarbmoylase 4)Dihydroorotate Dehydrogenase
1–>3–>2–>4 CPS2->Asp Transcarbomoylase->Dihydroorotase->Dihydroorotate Dehydrogenase
The Brain Prefers ___ but can use ___ as an energy source.
1) Glucose 2) Ketone Bodies
Results of 2,3BPG IN RBC’s ?
1) Glycolysis results in less ATP (2,3 BPG amount dependent) 2) Hemoglobin Binding - Oxygen release is Increased.
Carries most information on membrane topology of an ion channel: 1)Electromicroscopic image 2)The number and composition of subunits 3)Hydropathy plot 4)Molecular weight
3 Hydropathy plot Carries most information on membrane topology of an ion channel.
Consequence of inherited Adenosine Deaminase Deficiency?
Immunodeficiency
Serine, Alanine and Cysteine are all catabolyzed to form: 1)Alpha-Ketoglutarate 2)Succinate 3)Fumarate 4)Pyruvate 5)None of the above
4 Serine, Alanine and Cysteine are all catabolyzed to form: Pyruvate
Heparin is commonly used in treatment of Thrombosis because: 1)Inactivates Thrombin efficiently and directly. 2)Inhibits prothrombin activation by thrombin. 3)Facilitates thrombin inactivation by Antithrombin. 4)Enhances Plasmin efficiency.
3 Facilitates thrombin inactivation by Antithrombin.
Characteristics of Leptins: 1) These are Complex carbohydrates 2) Polypeptides produced by Adipocytes 3) There are types of obesities associates with their signal loss 4) Their production is proportional with the mass of Adipocytes. 5)High leptin level correlates to increased appetite.
2 , 3 , 4 Polypeptides produced by Adipocytes. There are types of obesities associates with their signal loss. Their production is proportional with the mass of Adipocytes.
Causes of Hyper-Homocysteine: 1)Lack of B6 2)Lack of B12 3)Enzyme Deficiency 4)Lack of Methionine
1 , 2 , 3 Lack of B6 or B12. Enzyme Deficiency - S-adenosylhomocysteinase. all cause Hyper-Homocysteine
Which deficiency could causes PKU: 1)Dihydrobiopterin reductase 2)Vitamnin B6 3)Phenylalanine Hydroxylase 4)Biopterin Synthesis 5)Vitamin C
1 , 3 ,4 Phenylalanine Hydroxylase - No outlet to Tyr Dihydrobiopterin reductase - No BH4 Co-factor Biopterin - No BH4 Co-factor
Which of the following is NOT common for FA Synthesis and Beta oxidation:
1) Acyl-CoA derivatives are intermediates
2) Double bonds are oxidized or Reduced by Pyrimidine nucleotide coenzymes.
3) These processes occur in Mito. Matrix
4) A derivative of Pantothenic acid is involved
3 is WRONG Beta oxidation happens in the mito. matrix while FA Synthesis in the Cytosol
True for synthesis of Norepinephrine:
1) Rate limiting step is Dopamine hydroxylase reaction 2)All pathway enzymes are located in NE axon terminal 3)Calcium activates Tyrosine Hydroxylase
4) Catechol-O-Methyltransferase doesn’t participate
3 , 4
In the synthesis of Norepinephrine:
Calcium activates Tyrosine Hydroxylase
Catechol-O-Methyltransferase doesn’t participate (COMT is for NE degradation)
The Ribosyl Phosphate needed for the synthesis of orotidylate, Inosinate and Guanylate is most directly provided by:
PRPP: 5-Phosphoribosyl-1-Pyrophosphate
True for Skeletal Muscle Lipid Metabolism:
1) LPL activity Increases in starvation
2) Synthesis of Ketone Bodies in starvation
3) In aerobic exercise conditions :Beta-Oxidation active
4) FA Oxidation - long term exercise energy supply
1 , 3 , 4
LPL activity Increases in starvation (Only in Muscle)
3) In aerobic exercise conditions : Beta-Oxidation active
4) FA Oxidation - long term exercise energy supply
In De-Novo Pyrimidine Synthesis which of these Enzymes is involved:
1) Adenine Phosphoribosyl transferase
2) Glutamine Phosphoribosyl-pyrophosphate amidotransferase
3) Orotic Acid Phosphoribosyl transferase
4) Hypoxanthine-Guanine Phosphoribosyl Transferase
5) Cytosine Phosphoribosyl Transferase
3
Orotic Acid Phosphoribosyl transferase is part of De-Novo Pyrimidine Synthesis.
Amino Acids with 2 Chiral Centers:
Threonine and Isoleucine
The amino acid that is released into the bloodstream by the muscle:
1) Trp
2) Val
3) Ala
4) Leu
The amino acid that is released into the bloodstream by the muscle Alanine.
Which CYPs are not participating in Aldosterone synthesis from Cholesterol: 1)Scc 2)17 Hydroxylase 3)2 Hydroxylase 4)Aromatase
2 , 4 17 Hydroxylase and Aromatase are not involved in Aldosterone synthesis.
Disease caused by Clc channel mutation: 1)Meysthenia 2)Myotonia 3)Epilepsy 4)Cystic fibrosis 5)Long QT syndrome
2 Myotonia
Order of Enzymes of Cateocholamines Synthesis (5+Cofactors):
- Tyrosine Hydroxylase
- Dopamine - Beta Hydroxylase
- Phenylalanine Hydroxylase
- DOPA Decarboxylase
- Phenyl-Ethanolamine-N-Methyltransferase
1) Phenylalanine Hydroxylase (BH4)
2) Tyrosine Hydroxylase (BH4)
3) DOPA Decarboxylase (PLP)
4) Dopamine - Beta Hydroxylase (Vit C/Ascorbate)
5) Phenyl-Ethanolamine-N-Methyltransferase (SAM)
Proteins participating in Reverse cholesterol transport:
1) ApoA1
2) LCAT
3) AopB48
4) ApoC2
5) LPL
1 , 2
ApoA1 activates LCAT - Esterifying Cholesterol
What Enzyme of the Glycolysis forms GTP?
None
Select the true statements: 1)Cholesterol is formed from HMG-CoA synthesized in the Mitochondria 2)Cholesterol is formed from HMG-CoA synthesized in the Cystosol 3)Mevalonatel is formed from HMG-CoA Carboxylation 4)NADPH is needed for Mevalonate Synthesis 5)Production of isopentenyl-pyrophoshate also requires a decarboxylase
2 , 4 , 5 2)Cholesterol is formed from HMG-CoA synthesized in the Cystosol 4)NADPH is needed for Mevalonate Synthesis 5)Production of isopentenyl-pyrophoshate also requires a decarboxylase
What binds the Sodium-Potassium ATPase on the outer membrane side:
1) Ouabain
2) Na+
3) K+
4) ATP
1 , 3
Ouabain and K
Squalene synthesis from farnesyl pyrophosphate results in the release of two moles of PPi for each Squalene. This is part of the Synthesis of:
1) Cholesterol
2) Pyrimidine
3) Pentose Phosphate Pathway
1) Cholesterol
Squalene synthesis from farnesyl pyrophosphate results in the release of two moles of PPi for each Squalene.
True for AMPK Phosphorylation in the muscle (Pick one):
1) Activates Glycogen Phosphorylase
2) Catalyzes F2P conversion to F2,6BP
3) Inactivates ACC thus decreases Malonyl-CoA con.
4) inactivates PDH - TCA Cycle inhibited 5)Activates FA Synthesis
3) Inactivates ACC thus decreases Malonyl-CoA con. More oxidizing less producing Fat Acids. gotta get those ATPs.
In the conversion of dUMP to dTMP the Methyl group donor is:
1) SAM
2) N5-N10-Methylyene Tetrahydrofolate
3) N5-Methyl Tetrahydrofolate
4) Tetrahydrofolate
2) N5-N10-Methylyene Tetrahydrofolate
Which of the following are involved in the uptake of cholesterol originating from peripheral tissues:
1) LDLR
2) Scavenger receptor A
3) Scavenger receptor B1
4) LXR
5) ABCA1
1 , 3
Scavenger receptor B1 and LDLR
In one cycle of Beta oxidation how many ATP would be formed?
1 NADH and 1 FADH2 formed will give off together: 4 ATP Molecules (2.5+1.5)
Which amino acid has the derivative of Melanin?
Tyrosine
All of the following are gluconeogenic enzymes, EXCEPT: 1)F1,6BPase
2) G6Pase
3) PK
4) PC
5) PEPCK
3
Pyruvate Kinase is Glycolytic.
What is the dominant Nucleophillic conjugation type in phase 2 Biotransformation:
Glucuronic acid Conjugation
What is the treatment for Hyperammonemia?
Sodium Phenylbutyrate and Sodium Benzoate. Both are alternative Nitrogen carriers - Mixed to form Lactulose. (Also low Protein diet).
True for Hemoglobin:
1) It is a tetramer
2) The Fe2+ moves into the plane of the heme on oxygenation.
3) The subunits have low affinity (T) state and High affinity in (R) State.
4) Bisphosphoglycerate stabilizes the R-form.
1 , 2 ,3
Hemoglobin is a tetramer, It’s Fe2+ moves into the plane of the heme on oxygenation. The subunits have low affinity (T) state and High affinity in (R) State.
Glutathione Reductase in RBC:
1) NADH Increase
2) H2O2 Increase
3) Removal of H202
4) Inhibits PPP
5) Reducing Glutathione for Glutathione Peroxidase reaction.
3 , 5 Glutathione Reductase in RBC: Removal of H202 + Reducing Glutathione for Glutathione Peroxidase reaction.
Balance of ATP Formation/Consumption of Anaerobic Glycolysis:
2 ATP consumed and 4 ATP formed
What is the committed step of of cholesterol biosynthesis?
HMG-CoA Reduction to Mevalonate by HMG-CoA Reductase.
Which of the following is a Proton pump in the Electron transport chain:
1) Ubiquinone
2) Complex II
3) Complex I
4) Cytochrome C
3
Complex I is a Proton Pump, the rest are simply passing along the Electrons
(Complex II = Succinate Dehydrogenase)
What are the two distinct activities of the Debranching Enzyme?
1) alpha-1-6 Glucosidase, Debranching Activity
2) Transferase Activity
In Prothrombin time assay (PT) we can learn about : 1)Factor VII 2)Factor V 3)Factor X 4)Factor XII 5)Factor XI
1 , 2 , 3 Factor VII, Factor V, Factor X - Belong to Extrinsic Pathway.
What is the common when Reaction when Hypoxanthine is converted to Xanthine and when Xanthine is converted to Uric Acid? Name the enzyme!
Oxygenation!
Xanthine Oxidase creates these Purine degredation products Hypoxanthine - 1 Oxygen Xanthine - 2 Oxygens Uric Acid - 3 Oxygens
False one for Ion channels:
1) Select among identically charged ions
2) Saturate at High ion concentration
3) Throughput rate approaches the Diffusion limit.
4) Transport Ions with their hydration shells
4 Ion channels mimic the Hydration shell while transfer the Ions without it.
What are the two basic Precursors forming Heme? Enzyme of the first step of the pathway?
Glycine and Succinyl-CoA
ALA Synthase
Treatment for Parkinson Disease (Pick one - Major)):
1) L-DOPA
2) MAO-B inhibitors
3) Peripheral Decarboxylase Inhibitors
4) Dopamine receptor agonists.
3
Treatment for Parkinson Disease is Peripheral Decarboxylase Inhibitors
True for StAR protein:
1) It is a Cholesterol Carrier
2) It promotes the cleavage of the 21-OH group
3) It promotes the cleavage cholesterol side chain with P450 which is found on the ER membrane.
4) It promotes the cleavage cholesterol side chain with P450 which is found in the Mitochondria.
1 , 4
It is carrying cholesterol into the close by Mitochondrion and therefore promoting its chance to be cleaved by CYP responsible for Side chain cleavage (Scc).
In Prothrombin time assay (PT) we can learn about : 1)Fibrinogen
2) Prothrombin
3) Factor VIII
4) Factor IX
5) Factor XI
Only 1 and 2!
PT checks the Extrinsic and Common pathway.
3 , 4 ,5 are Intrinsic Pathway.
Which are NOT classified as Ketone bodies : 1)Dihydroxyacetone 2)Acetoacetate 3)Beta-Hydroxybutyrate 4)Alpha-Hydroxybutyrate 5)Oxaloacetate
1 , 4 , 5 Dihydroxyacetone, Alpha-Hydroxybutyrate and Oxaloacetate are NOT Ketone bodies.
Perquisite for Thromboxane synthesis are:
1) Availability of phospholipid containing arachidonate for PLA2
2) Active Lipooxygenase
3) Functional COX
4) Corticosteroids do not inhibit COX
1 , 3 , 4
Availability of phospholipid containing arachidonate for PLA2, Functional COX, Corticosteroids do not inhibit COX are all needed for TXA2 formation.
What is the Location of Glucose-6-Phosphatase Enzyme:
Glucose-6-Phosphatase is on Endoplasmic reticulum
What is the basis of time-dependent changes in membrane permeability ?
Opening of discrete protein pores aka Ion Channels
Give at least 3 Functions of LXR:
1) Positive regulation of ABCA1 Transporter (also General cells)
2) Positive Regulation of CYP7A1 Enzyme (In the Liver)
3) IDOL All working to Reduce cellular Cholesterol Conc.
Which of the following provides Nitrogens to form Nucleotides: 1)Amido-groups of Gln 2)Amino-groups of Glu 3)Aspartate 4)Glycine 5)NH3
1 , 3 , 4 Amido-groups of Gln, Aspartate and Glycine are all providing Nitrogens for Nucleotide formation.
Are these sentences true? Is there any interrelation between them? 1)Hypertriglyceridemia favors the progression of Atherosclerosis. 2)The Cholesteryl-Ester transfer protein shuttles between HDL and VLDL , as well as between VLDL and LDL exchanging triacylglycerols for cholesterol esters.
Both are true: 2 )leads to 1)
Happens after 3 days of starvation:
1) Glutamine is released from the liver will be higher than Glutamate intake.
2) Glutamine is taken by the Kidney
3) Glutamine is taken by the Liver
4) Muscles will release a large amount of Amino acid
2 , 4 -
True after 3 days of starvation Glutamine is taken by the Kidney Muscles will release a large amount of Amino acid
What receptor in the CNS functions as a Na and Ca Channel?
NMDA
Threonine Dehydratase: Substrate, Product and Coenzyme.
Threonine Dehydratase: Substrate - Threonine Product - Alpha-ketobutyrate + Ammonia Coenzyme -PLP
Why Coumarol is an antithromobotic drug?
-Inhibits Vit K reduction thus preventing incorporation of gamma-Carboxyglutamate into prothrombin (and other Factors with Gla domain )
Function of NPC1L1 Transporter:
Pump in cholesterol into Epithelial Intestinal cells.
How many unitary charges allows activation of VDC?
12 -16
Possible utilization of Glucose in Erythrocytes (at least 2):
1) Anaerobic Glycolysis
2) Pentose Phosphate Pathway
3) Glucouranate Pathway
True for Nicotinic Ach receptor:
1) It is a Homopentamer, it dysfunction can lead to myasthenia.
2) It is a Heteropentamer, it dysfunction can lead to myasthenia.
3) It is a Tetramer, its dysfunction can lead to myotonia. 4)The ligand binding domain is a 4 fold symmetrical gating ring.
5) The ligand binding domain is a 5 fold symmetrical ring.
2 , 5
It is a Heteropentamer, it dysfunction can lead to myasthenia. The ligand binding domain is a 5 fold symmetrical ring.
Treatments for symptoms of Antiphospholipid syndrome:
1) Vit K
2) Vit K anatagonists
3) Folic Acid
4) Antifolates
5) Heparin
6) Protamine
2 , 5
Vitamin K antagonists and Heparin
Looking at a Lineweaver plot, If the enzyme linear function changed with inhibition in a way that Vmax and Km are lower, which inhibition occurred?
Uncompetitive inhibition decreases Vmax and Km.
Pituitary hormone promoting the conversion of cholesterol to Progenenolone in the gonads:
LH - Lutenizing Hormone
4 general types of Phase I reactions in Biotransformation:
1)Oxidation 2)Reduction 3)Hydrolysis 4)Hydration
Von Gierke Disease is caused by deficiency of : 1)Glycogen Synthase 2)Glycogen Phosphorylase 3)Glucose-6-Phosphatase 4)UDP-Glucose-Uridylyl transferase
3) Glucose-6-Phosphatase Deficiency. It is a glycogen storage disease when one cannot simply break down Glycogen = Accumulation, Lactic Acidosis, Hypoglycemia are the symptoms.
The synthesis of Purines and Pyrimidines differs in:
Purine synthesis starts with the formation of PRPP, whereas Pyrimidines incorporate the PRPP near the end of the Pathway.
In the Respiratory chain, ATP Synthase is inhibited by: 1)Oligomycin 2)Statins 3)Barbiturates 4)Cyanide
1 In the Respiratory chain, ATP Synthase is inhibited by Oligomycin.
Which is FALSE for starvation: 1)Kidney Glutaminase level is elevated 2)Glucagon activates Gluconeogenesis in the Kidney 3)Glutamine is a Glucose precursor in the kidney 4)Glucagon activates Gluconeogenesis in the Liver
2 Glucagon is not activating Gluconeogenesis in the Kidney but Catecholamines do.
In the Respiratory chain, Complex IV is inhibited by: 1)Oligomycin 2)Statins 3)Barbiturates 4)Cyanide
4 In the Respiratory chain Complex 4 is inhibited by Cyanide.
While in starvation state the Liver has an active: 1)Glut 2 2)Acetyl-CoA carboxylase 3)Hexokinase 4)PFK2
1 While in starvation state the Liver has an active Glut 2
10 ml of 0.1M Arg solution (starting from fully protonated form) is titrated with 0.1 N NaOH. At which of the NaOH additions do you expect buffer formation:
1) 5ml
2) 10ml
3) 15ml
4) 20ml
5) 25ml
1 , 3 , 5
5 , 15 and 25 ml will yield a Buffer solution.
Since 10, 20 , 30 ml will be the Eq points - Buffering in between them.
Its Eq point signfys the de-portonation of 1 functional group - 3 for Arg.
True for Neurons metabolism (MCQ):
1) The importance of PPP in neurons is negligible.
2) have Highly active Gln Synthase.
3) They are extremely sensitive to oxygen depletion.
4) Gln could be used as energy source.
5) Able to produce and consume Lactate.
3 , 4 , 5 are true for Neuron metabolism.
- They are extremely sensitive to oxygen depletion.
- Gln could be used as energy source.
- Able to produce and consume Lactate.
True for Ribonucleotide Reductase (MCQ):
1) Thioredoxin acts as an essential electron carrier
2) There is a separate enzyme for: ADP, CDP, GDP, UDP
3) Mechanism involves formation of Free Radical
4) Acts on Nucleotide Diphosphates
5) Glutathaione is Part of the Electron transfer
1 , 3 , 4 , 5
1) Thioredoxin acts as an essential electron carrier
3) Mechanism involves formation of Free Radical
4) Acts on Nucleotide Diphosphates
5) Glutathaione is Part of the Electron transfer
What is the difference in the Negative Feedback regulation of Hexokinase and Glucokinase?
Glucokinase is not inhibited back by G6P while Hexokinase Does. (But by Fructose 6 phosphate)
Which of Urea Cycle enzymes are located in the Mitochondria:
1) CPS1
2) Ornithine transcarbamoylase
3) Argininosuccinate Lyase
4) Argininosuccinate Synthetase
5) Arginase
1 , 2
Carbamoyl Phosphate Synthetase 1 (CPS1) and Ornithine transcarbamoylase are found in the Mitochondria.
SAM is a Methyl Donor in the Synthesis of:
1) Carnitine
2) Creatine
3) Choline
4) Epinephrine
All of them!
1)Carnitine 2)Creatine 3)Choline 4)Epinephrine
FALSE for Fatty Acid Elongation System (Pick one):
1) In SER
2) uses Malonyl-CoA
3) Produces Steroyl-CoA from Palmitoyl-CoA
4) Direct Precursor of Added Carbons is Acetyl-CoA
5) It involves same four step sequence of FA Synthase
4
Direct Precursor of Added Carbons is Acetyl-CoA
Give us GABA Shunt:
1) Ketoglutarate
* -Ketoglutarate DH*
2) Glutamate
* -Glutamate DH*
3) GABA
* -GABA Transaminase*
4) Succinate Semialdehyde
* -Succinate Semialdehyde DH*
5) Succinate
Are these two sentences true? Is there any connection?
1) Dopamine-Beta-Hydroxylase is localized in vesicles of noreadrenergic axons
2) Dopamine is formed in synaptic vesicles
1 is true but 2 is false.
Dopamine-Beta-Hydroxylase is localized in vesicles of noreadrenergic axons, this is why Noradrenaline is formed in synaptic vesicles.
Which Amino acids are purely Ketogenic?
Leucine and Lysine
What is the fate of the 1’ Carbon in Pentose Phosphate Pathway?
Becomes CO2
True for Alpha-2-Plasmin Inhibitor:
1) One of the most efficient (endo) protease inhibitors
2) It forms equimolar complex with plasmin leading to activity loss
3) Fibrin-bound plasmin is an easier target for it
4) It is bound to fibrin by FXIII
1 , 2 , 4
1) one of the most efficient (endo) protease inhibitors
2) It forms equimolar complex with plasmin leading to activity loss
4) It is bound to fibrin by FXIII
Mechailis-Menten Equation:
Vi = [S]xVmax / ([S] + Km)
Enzymes catalyzing the Nucleotide Salvage reactions : 1)Uridine Kinase
2) Cytidine Kinase
3) Aspartate Carbamoyltransferase
4) Hypoxanthine-Guanine-Phosphorybosil transferase
5) PRPP - Amidotransferase
1 , 2, 4
1) Uridine Kinase
2) Cytidine Kinase
4) Hypoxanthine-Guanine-Phosphorybosil transferase
(3 and 5 are for De-Novo)
What are the most important xenobiotics inducers of CYP1 ?
Polycyclic aromatic hydrocarbons
All of the following enzymes catalyze anaplerotic reactions except: 1)Pyruvate Dehydrogenase 2)Glutamate Dehydrogenase 3)Pyruvate Carboxylase 4)Phosphoenolpyruvate Carboxykinase
1 All of the following enzymes catalyze anaplerotic reactions except Pyruvate Dehydrogenase.
Why do endothelial cells Inhibit Platelet activation:
1) Synthesize and Secrete PGI2
2) Contain Ecto-ADPase
3) Produce Plasminogen Activators
4) Produce TFPI
1 , 2
- Synthesize and Secrete PGI2
- Contain Ecto-ADPase
Give at least 3 Functions of the Liver in Hemostasis:
- Synthesis of several coagulation factors - Gln to Gla conversion with Vit K - Take up inactive Fibrinolytic and Coagulation factors - Synthesis of Inhibitors of Fibrinolysis and Coagulation
Which enzyme catalyzes the reaction below: Substrates: Phosphatadylcholine+Cholesterol Products: Lysophosphatadylcholine + Cholesterol Ester Where does this occurs?
LCAT - Lecthin-cholesterol acyltransferase. Occurs in circulatory system (Plasma).
In Orotic Aciduria - what will Uridine consumption cause?
UMP formation and nucleotide formation will be possible - It is the treatment.
Triggers for Platelets activation:
1) Tissue factor
2) Thrombin
3) Collagen
4) PAF
5) Factor XIIa
2 , 3 , 4
Thrombin -Collagen -PAF
After long starvation the Renal Cortex starts _____ activated by _____ .
After long starvation the Renal Cortex starts Gluconeogenesis activated by Epi/Norepi.
Check if the following sentences are True and have any connection:
1) Both phosphoenolpyruvate and ATP contain high-energy phosphate bonds.
2) The reaction catalyzed by Pyruvate Kinase is Reversible.
Statement 1 is True but 2 is False.
1) Both phosphoenolpyruvate and ATP contain high-energy phosphate bonds.
2) The reaction catalyzed by Pyruvate Kinase is actually IRREVERSIBLE.
Fructose 1 , 6 Bisphosphatase has a key role in Gluconeogenesis. Its allosteric Modulators:
1) F1,6BP
2) F2,6BP
3) Citrate
4) AMP
5) ADP
2 , 4
F2,6BP and AMP activate the Kinase part of this Tandem enzyme - Stopping Gluconeogensis and Activating Glycolysis.
Which amino acids has a Guanidino group in its side chain:
1) His
2) Lys
3) Tyr
4) Arg
5) Tyr
4
Arginine has a Guanidino group in its side chain.
The binding of oxygen to Hemoglobin relationship curve looks:
1) Sigmoidal
2) Linear - Positive
3) Linear - Negative
4) Hyperbolic
1
Sigmoidal
Which molecular events contribute to the Chronotropic effect of NE:
1) Activation of PKA
2) Sigma 2 receptor activation
3) Dephosphorylation of Phospholamban
4) Increased Ca concentration Intracellularly
5) Activation of Sarcoplasmic Reticulum Ca ATPase
1 , 4 , 5
Activation of PKA will cause activation of DHP, RYR and SERCA which will cause faster and stronger Ca signals cycles.
Substrates of Thrombin:
1) Fibrin
2) Factor V
3) Factor VI
4) Factor VIII
5) Factor XI
2 , 4 , 5
- Factor V
- Factor VIII
- Factor XI
(Also factors XIII and Fibrinogen)
Looking at a Lineweaver plot, If the enzyme linear function changed with inhibition in a way that Vmax is lower, which inhibition occurred?
Non-Competitive inhibition decreases Vmax.
True for White Adipose tissue metabolism:
1) High rate of Glycolysis in well fed state.
2) Leptin inversely correlates with the Mass of them.
3) Glycolysis is essential for the esterification of fatty acids in these cells.
4) Lipoprotein lipase is activated by physical exercise in the capillaries of fatty tissue.
5) Glucose uptake is Insulin dependent in them.
1 , 3 , 5 are true for White Adipocytes Metabolism
1) High rate of Glycolysis in well fed state.
3) Glycolysis is essential for the esterification of fatty acids in these cells.
5) Glucose uptake is Insulin dependent in them.
Biotin is a co-factor for these enzymes: 1)Phosphoenolpyruvate Carboxykinase
2) Pyruvate Carboxylase
3) Pyruvate Dehydrogenase
4) Acetyl-CoA Carboxylase
5) Propionyl-CoA Carboxylase
2 , 4 , 5
Biotin is a Carboxyl group carrier so it is involved in carboxylation reactions (not all)
Which of the following could be converted to Serine in a single Step (Pick one):
1) Pyruvate
2) Citric Acid Cycle Intermediates
3) Ornithine Cycle Intermediates
4) Glycine
5) Choline
4
Glycine is converted to Serine in one step
Serine hydroxymethyl transferase catalyzes this reversible reaction.
Role of FXII in blood coagulation:
1) Initiate the blood coagulation cascade
2) Induce fibrinolysis
3) May cause Vasoconstriction
4) May cause Vasodilation
5) Useful for diagnosis of factor defects
1 , 2 , 3 , 4 , 5
1) Initiates the blood coagulation cascade
2) Induce Fibrinolysis
3) May cause Vasoconstriction (Kalkrein)
4) May cause Vasodilation (Kalkrein)
5) Useful for diagnosis of factor defects
What are the 3 different modes of regulation of HMG-CoA Reductase?
Regulation of HMG-CoA Reductase:
1)Induction
2)Allosteric Inhibition
3)Protein Degradation
Chylomicrons:
1) Are secreted by hepatocytes
2) Contain ApoB100
3) Accumulated in familial lipoprotein lipase deficiency
4) TAG content is hydrolyzed by HSL
5) TAG content is hydrolyzed by Lipoprotein lIpase
3 , 5
Chylomicrons TAG content is hydrolyzed by Lipoprotein lIpase and they accumulate in familial lipoprotein lipase deficiency
Insulin is an example of a(n) _____ hormone.
Insulin is an example of a Peptide hormone.
What are the biological roles of Bile Acids:
1) They contribute to the activation of pancreatic lipase in the intestine.
2) Their micelles are essential for cholesterol absorption in the intestine.
3) They are ligands of FXR
4) Their micelles are essential for cholesterol disposal in the intestine.
5) They are ligands of LXR
1 , 2 ,3 , 4
1) They contribute to the activation of pancreatic lipase in the intestine.
2) Their micelles are essential for cholesterol absorption in the intestine.
3) They are ligands of FXR
4) Their micelles are essential for cholesterol disposal in the intestine.
What is the main effector of Cooperativity in case of Glucokinase?
Glucose Cellular Concentration
What will rule out the possibility of Reaction coupling between two reactions?
1) Activation Energy for both reactions is High.
2) The Delta-G sign for both reactions is the same.
The following hormones activate Adenylate cyclase through Gs mechanism:
1) Glucagon
2) Insulin
3) Histamine
4) Vit D
5) Adrenaline
1 , 3 , 5
Glucagon Histamine Adrenaline
Starvation results in decreased activity of (MCQ):
1) Hexokinase
2) Glucokinase
3) PDH
4) PK
5) PC
2 , 3 , 4
Glucokinase , PDH , PK
True for Bile acids:
1) Synthesized in the Intestine
2) Their polarity increase in the synthesis process
3) They are needed for the solubilization of Cholesterol
4) Deoxycholic is one of the primary bile acids
5) Lack of bile acid results in steatrorhea
2) Their polarity increase in the synthesis process
3) They are needed for the solubilization of Cholesterol
5) Lack of bile acid results in steatrorhea
Which of the following proteins is an oxygen sensitive gene product: 1)Hexokinase 2)VEGF 3)Erythropoetin 4)GLUT1
1 , 2 , 3 , 4 Hexokinase, VEGF, Erythropoetin ans GLUT1 are all products of HIF1 induction in Hypoxia.
When Glucagon level in blood is rising which enzyme activity decreases in the Liver: 1)Pyruvate Kinase 2)Pyruvate Carboxylase 3)PEPCK 4)PDH 5)PFK1
1 , 4 , 5 Glucagon inhibits the Glycolytic enzymes:PK, PDH, PFK1.
____ is synthesized in the Zona Glomerulosa and metabolized to form Tetrahydro______-3-glucuronide in the liver and removed in the Liver.
Aldosterone is synthesized in the Zona Glomerulosa and metabolized to form Tetrahydroaldosterone-3-glucuronide in the liver and removed in the Liver.
Which Amino Acids are forming Alpha-KG
1) Proline 2) Glutamate 3) Glutamine 4) Arginine 5) Histidine
In anaerobic muscle preparation lactate formed from glucose labeled in C2 would be labeled in : 1)All three carbon atoms 2)The carboxyl atoms only 3)The carbon carrying the OH only 4)Methyl Carbon only 5)Methyl and Carboxyl Carbons
3 The carbon carrying the OH only
What is common for the regulation of Glycogen Phosphrylase and Phosphorylase Kinase?
Both are Active upon Phosphorylation.
Activation of Pancreatic Lipase?
Co-lipase activates in the Duodenum
True for Steps of Heme Bio-transformation:
1) Heme is hydrolyzed and Forms Bilirubin
2) Heme is Reduced and Forms Bilirubin
3) Heme is Oxidized and forms Bilirubin
4) Bilirubin is conjugated with two Glucose molecules
5) Bilirubin is conjugated with Glucuronate
True for Steps of Heme Bio-transformation:
Heme is Oxidized and forms Bilirubin
Bilirubin is conjugated with Glucuronate
When oxygen binds a heme-containing protein, two open coordination bonds of Fe2+ are occupied by :
1) 2 Oxygen atoms
2) Oxygen molecule and Histidine Nitrogen atom.
3) Oxygen molecule and Heme Nitrogen atom.
4) 2 Oxygen molecules
5) Oxygen atom and Histidine Nitrogen atom.
2
In Oxyhemoglobin coordination bonds of Fe2+ are linked to Oxygen molecule and Histidine Nitrogen atom.
Type I (Red) fibers :
1) has low Myoglobin content
2) has low glycolytic capacity
3) has low amount of blood vessels
4) Has low TAG content
2
Type I (Red) fibers has low glycolytic capacity
Hemophilia enzyme deficiency?
Hemophilia A - Factor VIII
Hemophilia B - Factor IX
Hemophilia C - Factor XI
True for Astroglia Metabolism:
1) Astrocytes has the greatest CNS Glycogen amount.
2) Astrocytes have less mitochondria than Neurons
3) Astrocytes convert Gln to Glu
4) Astrocytes take up Lactate produced by Neurons
5) Pyruvate Carboxylase is localized in Astrocytes
1 , 2 , 5 are true.
3 - Astrocytes actually convert Glu to Gln.
4 - NEURONS take up Lactate produced by ASTROGLIA.
Turnover number formula :
Vmax / E E = Concentration of enzyme
What are true for the very long term starvation (longer than one week):
1) Stress hormones initiate gluconeogenesis in the kidney.
2) Gluconeogenesis in the Liver is decreased by acidosis.
3) Ketone bodies production decreases as starvation proceeds.
4) Ketone bodies suppress proteolysis
5) The serum level of FFAs increase
1 , 2 ,4 , 5
1) Stress hormones initiate gluconeogenesis in the kidney.
2) Gluconeogenesis in the Liver is decreased by acidosis.
4) Ketone bodies suppress proteolysis
5) The serum level of FFAs increase
Correct order of Enzymes for FA Synthesis:
- Ketoacyl Reductase
- Hydroxyacyl Dehydratase
- Thioesterase
- Enoyl Reductase
1) Ketoacyl Reductase
2) Hydroxyacyl Dehydratase
3) Enoyl Reductase
4) Thioesterase
True for Digestive Enzymes:
1) Carboxypeptidase is a Carboxyl Protease
2) Elastase and Pepsin are Thiolprotease
3) No Zn+ Could be found in the GI enzymes system
4) Trypsin and Chymotrypsin are Serine Proteases
Only 4
Trypsin and Chymotrypsin are Serine Proteases
examples for ____ are deoxycholic acid and LIthocholic acid.
examples for Secondary Bile Acids are deoxycholic acid and LIthocholic acid.
The Lineweaver -Burk plot:
1) Is a double reciprocal presentation of the Michaelis-Menten Equation.
2) Simplifies the determination of Km and Vmax.
3) Is used to calculate the degree of cooperativity among enzyme subunits.
4) Is a one-side reciprocal presentation of the Michaelis-Menten Equation.
1 , 2
The Lineweaver -Burk plot is a double reciprocal presentation of the Michaelis-Menten Equation, that simplifies the determination of Km and Vmax.
Following glycogenolysis Glucose-1-P is converted next to:
Glucose-6-P
True for Neurons Metabolism:
1) Use nearly full capacity of their oxidative energy production.
2) High rate of uptake and utilization of Branched Chain amino acids.
3) Free NH4 will be decreased by High activity of Glutamate Dehydrogenase
4) Ketone Bodies can partially replace Glucose as an energy source.
5) High rate of De-Novo fatty acid synthesis.
1 , 2 , 4 , 5
1) Use nearly full capacity of their oxidative energy production.
2) High rate of uptake and utilization of Branched Chain amino acids.
4) Ketone Bodies can partially replace Glucose as an energy source.
5) High rate of De-Novo fatty acid synthesis.
Choose the Inhibitory Allosteric effectors of PFK1:
1) ATP
2) Citrate
3) ADP
4) F2,6BP
5) AMP
6) H+
1 , 2 , 6
ATP , Citrate , H+
(ADP, F2,6BP and AMP are Allosteric Activators)
Which of the following amino acids contain 6 carbons: 1)Leu
2) Ile
3) Ala
4) Arg
5) Lys
6) Gln
1 , 2 , 4 , 5
Leucine, Isoleucine, Arginine and Lysine all have 6 Carbon atoms
Order the following tissues from Highest to Lowest energy content: Liver, Muscle , Blood, Adipose Tissue
1)Adipose Tissue 2)Muscle 3)Liver 4)Blood
Function of SRB1 :
Selective cholesterol uptake from HDL
What is the most important Anapleorotic Process in the muscle: 1)Pyruvate Carboxylase reaction 2)Purine Nucleotide Cycle 3)Glutamate Dehydrogenase 4)PEPCK
2
Most important Anapleorotic Process in the muscle is Purine Nucleotide Cycle because it forms Fumarate.
And muscles contruits to ammonia elimination + do not need nucleotide synthesis as much
Not true for Phospholemman (FXYD1): 1)Present in the heart 2)Activates Na/K ATPase 3)It is a subunit of Na/K ATPase 4)PKA phosphorylates it
2 Phospholemman (FXYD1) upon phosphorylation has less affinity to Na+. This is an Adrenergic B1 effect preventing arrhythmia
Which enzyme catalyzes the NADH producing step of Glycolysis?
Glyceraldehyde 3 Phosphate Dehydrogenase (GAPD)
Kendrew’s studies of Moglobin structure demonstrated that:
Myoglobin structure was very compact, with virtually no internal space available for water molecules.
Which are one step reactions:
1) Pyruvate - > Alanine
2) Arginine ->Creatinine
3) Serine->Choline
4) Serine - > Glycine
5) Aspartate - > Oxaloacetate
1 , 4 , 5
1) Pyruvate - > Alanine
4) Serine - > Glycine
5) Aspartate - > Oxaloacetate
True for sphingolipid synthesis (Pick one):
1) All carbons of Palmitate and Serine are incorporated into sphingosine.
2) Phosphatidic acid is the key intermediate in the pathway
3) CDP-sphingosine is the activated intermediate
4) CO2 is produced during the synthesis of Ceramide from Palmitate and Serine.
5) Glucose-6-P is the direct precursor of the Glucose is cerebrosides.
4
CO2 is produced during the synthesis of Ceramide from Palmitate and Serine.
Neurotransmitters are transported into Synaptic vesicles. Which protein is not part of this: 1)VAchT 2)VGLUT 3)SERT 4)V-type-ATPase
3 SERT is actually related to Serotonin reuptake.
If a cell has adequate supply of Adenine nucleotides but requires more guanine nucleotides: 1)Glutamine-PRPP amidotransferase will not be fully activated 2)AMP will feedback inhibitor of condensation of IMP with Aspartate. 3)ATP will stimulate the production of GMP from IMP. 4)ATP will inhibit IMP dehydrogenase
1 , 2 , 3 -Glutamine-PRPP amidotransferase will not be fully activated - Negative feedback from AMP Product. -AMP will feedback inhibitor of condensation of IMP with Aspartate + Less GTP needed in Purine Nucleotide cycle. -ATP will stimulate the production of GMP from IMP.
Which of the following fates are probable for Glutamate after synaptic transmission: 1)Glutamate can enter the postsynaptic neurons by inotropic receptors. 2)Glutamate Dehydrogenase splits the molecule in the synaptic cleft. 3)Glutamate will be taken back to Astrocytes by Na-Co-transport. 4)Glutamate will be transformed to Glutamine in Astrocytes.
3 , 4 Glutamate will be taken back to Astrocytes by Na-Co-transport than it will be transformed to Glutamine in Astrocytes.
In Glycogenolysis the enzyme ______ breaks an _____ bond to release a molecule of _____ .
In Glycogenolysis the enzyme Glycogen Phosphorylase breaks an Alpha 1-4 bond to release a molecule of Glucose-1-P.
How does synthesis of Purines and Pyrimidines differs in regard to incorporation of PRPP?
Purine synthesis starts with the formation of PRPP, whereas Pyrimidines incorporate the PRPP near the end of the Pathway.
What Amino Acids will form Succinyl-CoA?
1)Ile 2)Val 3)Met 4)Thr
Minimal Glucose input for production of 1 Molecule of Cholesterol:
9 molecules of Glucose. 30 Carbons are needed. Keep in mind each glucose gives 4 C to form 2 Acetyl-CoAs.
Gamma-Carboxy-Glutamate (Gla) is an amino acid present in the structure of several hemostatic factors and bone proteins. which statements are valid for Gla. which statements are true for Gla:
1) Gla has more negative charges than glutamate and so its side chain can bind cationic phospholipids.
2) Gla has more negative charges than glutamate and so its side chain can repulse anionic phospholipids.
3) Gla residues for a chelate with Ca
4) Vitamin K epoxide is needed for the synthesis of Gla
5) Warferin binds Vitamin K and thus prevents Gla synthesis.
Only 3!
Gla residues for a chelate with Ca. If you take a look in Kolev’s slides, there is a picture indicating how Gla domains are formed - it rules out 4 and 5.
Are these two sentences true? Is there any connection? 1)Activity of Hexokinase is higher at lower glucose concentrations than that of Glucokinase assuming equal Vmax. 2)Km value of Hexokinase is lower.
Both are true. HK has a lower Km we understand it has higher affinity to Glucose than GK and that’s why HK will be more active even in low concentrations.
Glutamine is the Nitrogen donor in synthesis of: 1)Inosinate (IMP) 2) Orotate 3) UMP 4) CTP 5) All
5) All: Inosinate (IMP) Orotate UMP CTP
G6PD Deficiency Consequence?
1)Less NADPH 2)More Glutathiones are in oxidized form 3)More Methemoglobin is formed under physiological conditions 4) Oxidizing Agents oxidize H2O2
Which of the following reactions with Folic acid (F) are Irreversible:
1) N10-N5-Methylene THF to N5-Methyl-THF
2) N10-N5-Methylene THF to N5-Oxymethyl-THF
3) N5-Foromino-THF to N10-FormyL-THF
4) N10-N5-Methenyl THF to N10-N5-Methylene THF
5) N5-Methyl-THF to THF
1 , 5
1) N10-N5-Methylene THF to N5-Methyl-THF
5) N5-Methyl-THF to THF
Which of the following participates in the regulation of Glycolysis (in the liver):
1) Beta-Receptor
2) Protein Kinase A
3) cAMP
4) Gs Protein
5) Gi Protein
6) Phosphoprotein Phosphatase
2 , 3 , 4 , 6
Protein Kinase A cAMP Gs Protein (Glucagon receptor)
PP1 (from Insulin’s stimulation of PFK2)
(1 - Liver adrenaline receptor is Alpha-1)
Choose the Positive allosteric effectors of PFK1: 1)ATP 2)Citrate 3)ADP 4)F2,6BP 5)AMP 6)H+
3 , 4 , 5 F2,6BP , AMP , ADP
_____ activates pancreatic lipase in the presence of colipase and triglyceride containing Micelles.
Primary Bile Acids activates pancreatic lipase in the presence of colipase and triglyceride containing Micelles.
Correct statements for Tetrahydrofolate: 1)Can receive a methyl group from Gly, Ser, Trp, His 2)its derivatives are interconvertable 3)Can donate Methyl group to Met 4)All are correct
1 , 2 Can receive a methyl group from Gly, Ser, Trp, His its derivatives are interconvertable
What inhibits PRPP Glutamyl amidotransferase: 1)AMP 2)IMP 3)NADH 4)PRPP
1 , 2 Negative feedbacking that shit
Order of Elements in the Major route of Extra-hepatic tissue Cholesterol to disposal as Bile Salts in the Intestines: 1) LDL 2) HDL 3) CETP 4) LPL 5)Hepatic Lipase 6)LDLR 7)CYP7A 8)ABCA Transporter
8 , 2 , 3 , 1 , 6 , 7
Correct order for enzymes of FA Synthesis: 1) Acetyl-CoA Carboxylase 2) Ketoacyl Reductase 3) Malonyl- transacylase 4) Acetyl-Acyl-transacylase 5) Ketoacyl-Synthase
- > Acetyl-CoA Carboxylase - > Acetyl-Acyl-transacylase - > Malonyl- transacylase - > Ketoacyl-Synthase - > Ketoacyl Reductase
Biotransformation Typical Phase I reaction is : 1)Sulfatation 2)Glutathionation 3)Alklylation 4)Oxidation 5)Acetylation
4)Oxidation (or Hydroxylation) By Cytochrome P450 enzymes
IDOL Protein: Expression Regulation and Function?
Expression is under control of LXR - High Cholesterol. IDOL increases the degredation of LDLR.
True for Bile acids synthesis in the Liver:
1) They activate the participating Hydroxylase enzymes
2) The first step is formation of 7-Alpha-hydroxycholsterol.
3) 7-Hydroxylase activity is inhibited by bile acids.
4) Lithocholic acid is formed in several steps from 11-hydroxycholsterol
5) Cholic acid formed form 11-hydroxycholesterol can be conjugated with Taurin.
2 , 3 are true for Bile acids synthesis.
The first step is formation of 7-Alpha-hydroxycholsterol catalyzed by 7-Hydroxylase activity is inhibited by (FXR Which ligands are) bile acids.
___ is giving Cholesterol Esters to ___ in exchange for getting back TAGs, this is supported by CETP.
HDL3 is giving Cholesterol esters to VLDL in exchange for getting TAG , this is supported by CETP.
Definition of Turnover Number
Maximum Number of Substrate converted to Product per second by each active site (unit s-1)
Which of the following cannot contribute to Gluconeogenesis: 1)Alanine 2)Palmitate 3)Alpha-Ketoglutarate 4)Glutamate 5)Pyruvate
2 Palmitate
Which has no role in the cellular effects of Muscarinic Receptor activation: 1)Increase in Calcium concentration intracellularlly 2)Activation of PLC 3)Na uptake 4)Activation of K channel 5)Activation of G protein.
3)Na uptake Not part of Muscarinic Receptor activation processes.
The product of glutathione peroxidase catalyzed reaction is: 1)NADH 2)H2O 3)H2O2 4)ATP
2 The product of glutathione peroxidase catalyzed reaction is H2O.
Cells expressing Liver-X-receptor are: 1)Hepatocyte 2)Enterocyte 3)Macrophage 4)Adipocyte 5)Pneumocyte
ALL are expressing LXR but the Liver has the highest expression of it, hence the name.
Which of the following mechanisms are characteristic for the ER: 1) SERCA 2)PMCA 3)IP3 Receptor 4)RYR 5)Sodium-Calcium exchanger
1 , 3 , 4 PMCA - Plasma membrane Calcium ATPase Na/Ca Exchanger is on Mitochondrial and Plasma Membranes
Are these two sentences true? Is there any connection? 1)The regeneration of S-adenosylmethionine doesnt require energy 2)Methyl group is directly transferred from Methyl-H4folate to S-Adenosylhomocysteine.
Both are FALSE! ATP is required in SAM regeneration. and Methyl group is directly transferred from Methyl-H4folate to Homocysteine (not SAH)
When will Tissue factor appear in blood: 1)Bacterial Infection 2)Embryo Death during Pregnancy 3)Snake Bite 4)Surgery
3 , 4 Only when Subendothelial tissue is exposed to the blood vessel lumen the TF appears.
True for K+ VDC: 1)Octamer of 4xKIR and 4xSUR 2)Tetramer of 4xSUR 3)Tetramer of 4xKIR 4)Inhibited by sulfonylureas 5)Inhibited by Dizoxine
3 K+ Voltage dependent channels are made of 4 KIR subunits.
_____ has a Omega-6, 20:4 and Delta 5, 8, 11, 14 structure it is precursor for Eicosanoids. ___ and ___ are examples for Eicosanoids.
Arachidonic Acid has a Omega-6, 20:4 and Delta 5, 8, 11, 14 structure it is precursor for Eicosanoids. TXA2 and PGF2 are examples for Eicosanoids.
FALSE for Na-K ATPae: 1)Ouabain binds on the Extracellular side 2)It results in a High concentration of K in the Cell 3)E1 state has a low affinity to ATP 4)E2 state has a low affinity to ATP
3 Na-K ATPae E1 state has actually a HIGH affinity to ATP
Which are True for Hemoglobin tetramer: 1)Hemoglobin has 4 heme groups 2)Hemoglobin binds a maximum of 4 O2 3)Hemoglobin binds 4 BPG molecules
1 , 2 Hemoglobin has 4 heme groups therefore it binds a maximum of 4 O2.
The steps of Glycolysis between Glyceraldehyde-3-P and 3-Phosphoglycerate involve all EXCEPT: 1)ATP Synthesis 2)Utilization of Pi 3)Oxidation of NADH to NAD+ 4)Formation of 1,3 Bisphophoglycerate 5)Catalysis by Phosphoglycerate Kinase
3 is Wrong! NAD+ is actually being reduced to NADH in GAP dehydrogenase reaction.
Lipoprotein lipase hydrolyzes TAGs of (MCQ): 1)VLDL 2)Nascent Chylomicron 3)Mature Chylomicron 4)Chylomicron Remnant 5)IDL
1 and 3 VLDL and Mature Chylomicron
which one is not a PDE inhibitor: 1)Caffeine 2)Mehtylxanthine 3)Theophylline 4)Aspirin
4 Aspirin is not a PDE inhibitor.
Select the correct statements: 1)HSL cleaves all 3 Fatty acids from TAG 2)Adipocytes express HSL 3)Phosphorylated form of HSL is Inactive 4)The-TAG derived glycerol cannot be phophorylated in adipocytes. 5)The Liver and the Intestine express Glycerol Kinase
2 , 4 , 5 2)Adipocytes express HSL. 4)The-TAG derived glycerol cannot be phophorylated in adipocytes. 5)The Liver and the Intestine express Glycerol Kinase.
What is the first ATP producing step of Glycoslysis?
1, 3 Bisphosphoglycerate to 3 Phosphoglycerate by 3-Phosphoglycerate Kinase
Select the FALSE statement: 1)Methemoglobin Reductase converts Hemoglobin ferric to ferrous Ion. 2)Ferric Hemoglobin forms in Healthy people as well. 3)Mutation of proximal His to Tyr results in Methemoglobinemia. 4)Imbalanced production of globin chains results in sickle-cell anemia. 5)Deoxy-Hemoglobin aggregates may from in RBCs of people having hemoglobin-S
4 is FALSE Imbalanced production of globin chains results in Thalassemia NOT sickle-cell anemia.
What are the Essential amino acids? Why are they essential?
PVT TIM HALL or PIMP in VAL Thorens - so easy . Phe , Val , Trp , Thr , Ile , Met , His , Arg , Leu , Lys We cannot synthesize them. Arg is Semi-Essential.
True for ABCA1 Transporter: 1)It is the major transporter of bile salts. 2)LDL binds to it 3)HDL bind to it. 4)It is necessary for the efflux of cholesterol from cells 5)High cellular cholesterol content stimulates its transcription.
3 , 4 , 5 ABCA1 Transporter binds HDL. Is necessary for the efflux of choleste rol from cells and High cellular cholesterol content stimulates its transcription.
A cell that is unable to obtain Tetrahydrofolate would be probably deficient in the biosynthesis of: 1)Orotate 2)Thymidylate 3)CMP 4)UMP 5)All of the above
2 Thymidylate synthase reaction requires THF as a methyl group donor.
Glycogen branching enzyme catalyzes (Choose one): 1) Degradation of glycogen tree branches 2) Alpha 1-6 bonds formation 3)Alpha 1-4 bonds formation 4)Removal of unneeded Glucose residues at the end of the branch.
2 Alpha 1-6 bonds formation are for the branching points. Alpha 1-4 are for the chain bonds.
Which Enzyme is defective in the Lesch-Nyhan Syndrome?
HPRT: Hypoxanthine-Guanine Phosphoribisyltransferase
During acidosis the Urea cycle: 1)Slows down 2)Speeds up 3)Unchanged
During acidosis the Urea cycle slows down.
True for Competitive Inhibition: 1)Km elevates 2)Vmax elevates 3)Fractional activity of enzyme is smaller at higher concentrations of the substrate. 4)Fractional activity of Inhibitor is smaller at higher concentrations of the substrate.
1 , 4 In Competitive Inhibition Km elevates and Fractional activity of Inhibitor is smaller at higher concentrations of the substrate.
What is the mechanism of Aspirin inhibition of COX1?
Irreversible Acetylation
Choose the correct statement: 1)Cyclooxygenase contains one (of two) active center with Heme 2)Ser-530 of COX is acetylated by Aspirin 3)Cyclooxygenase is a mem. bound monotopic enzyme 4)Cyclooxygenase active form is as monomers 5)Cyclooxygenases are suicides enzymes
2 , 5 During activity Cyclooxygenase destruct themselves Suicide enzymes. Ser-530 of COX is acetylated by Aspirin.
ABCG5/G8 Function:
Pump out cholesterol (of Hepatocytes) into Billiary capillaries
Endogenous inhibitors of Thrombin: 1)Heparin 2)Heparan Sulfate 3)Antithrombin 4)Thrombomodulin 5)Alpha-1-Protease inhibitor
3 , 5 3)Antithrombin 5)Alpha-1-Protease inhibitor
Choose the elements involved in Cysteine formation: 1)Methionine 2)Adenosylhomocysteinase 3)Serine 4)Cystathaione Synthase 5)Cystathionase
2 , 3 , 4 , 5 - Parts of the SAM Cycle.
Methionine is also part of it, but more distant (depends on the answer combo)
True for FXR: 1)Its expression is restricted to the Liver. 2)Its major ligand is the lithocholic acid. 3)Responsible for Negative regulation of ABCA1 4)Responsible for Negative regulation of CYP7A1 5)Higher level of active FXR results in enhancement of bile acid reabsorption in the Ileum.
3 , 4 , 5 FXR is responsible for Negative regulation of ABCA1 and CYP7A1. Higher level of active FXR results in enhancement of bile acid reabsorption in the Ileum.
When there is Beta-Oxidation of Odd number Fatty acid, the final product is____ and it is Converted to D-Methmalonyl-CoA by _____ with ____ as Cofactor.
When there is Beta-Oxidation of Odd number Fatty acid, the final product is Propionyl-CoA and it is Converted to D-Methmalonyl-CoA by Propionyl-CoA Carboxylase with Biotin as Cofactor.
A transition state analouge: 1)Resembles the active site of general acid-base enzymes. 2)typically reacts more rapidally with enzyme than the normal substrate. 3)Is less stable when binding to an enzyme than the normal substrate 4)stabilizes the transition state for the normal enzyme-substrate complex 5)Resembles the transition state structure of the normal enzyme substrate complex.
5 Transition state analouge resembles the transition state structure of the normal enzyme substrate complex.
True for Serotonin: 1)It is the main product of Tryptophan catabolism 2)Serotonin is 5-Hydroxy-Trypamine. 3)Its Synthesis requires Tetrahydrobiopterine. 4)Its Synthesis requires Tetrahydrofolate. 5)It plays a role in the regulation of Sleep.
1 , 2 , 3 , 5 Serotonin is formed in a pathway from Tryptophan by Trp Hydroxylase (Tetrahydrobiopterine) and Aromatic AA Decarboxylase (PLP). It regulates mood and sleep.
Activation of PKC is: 1)Calcium dependent 2)Calcium independent 3)DAG Dependent 4)Phorbol Ester dependent 5)Phospholipid dependent
1 , 2 , 3 , 4 , 5 (Phorbol esters are DAG analogues)
In the synthesis of Phosphatadylcholine from phosphatadylethanolamine the methyl group donor is: 1)Methanol 2)S-Adenosylmethionine 3)Tetrahydrofolate derivative 4)Choline 5)Serine
2 S-Adenosylmethionine is the methyl donor in the formation of Phosphatadylcholine.
Are the two following statements true? Is there any connection between them? 1) Beta-1 receptor stimulation results in release of Ca from Sarcoplasmic reticulum in the Heart muscle cell 2)Beta-1 receptor stimulation results in the activation of the Sarcoplasmic Ca-ATPase
Both statments are true. PKA is active in both. 1) PKA activates DHP+RYR channels (early) 2) PKA activates SERCA through Phosphlamban (late)
Which of the Following catalyzes a reaction with Ammonia: 1)Arginase 2)Glutamate Dehydrogenase 3)AMP Deaminase 4)Glutaminase 5)AMP Synthase
1 , 2 , 3 , 4 1)Arginase 2)Glutamate Dehydrogenase 3)AMP Deaminase 4)Glutaminase
What is the link to SAM cycle (step) of the Folate cycle which Irreversible? Why?
N5-Methy-THF to THF. Methyl group donation.
Which is the main apoprotein component of nascent chylomicron: 1)ApoCII 2)ApoA1 3)ApoB48 4)ApoB100
3 ApoB48 - Chylomicron Cholesterol transport ApoB100 - LDLRs ApoE - Cleavage of Remenants ApoA1 - HDL LCATs ApoCII - Chylomicron and VLDL - LPLs Activation
Products of Prostanoids formation:
1)PGI2 2)PGE2 3)PGD2 4)PGF2-Alpha
Amylase substrates: 1)Glycogen 2)Maltose 3)Amylopectin 4)Maltriose 5)Isomaltose
1 , 3 Amylase substrates are Glycogen and Amylopectin. Amylase Products are Maltose, Maltriose and Isomaltose.
True for vWF: 1)Activates Tenase complex 2)Activate in a Multimeric form 3)Activate in a Monomeric form 4)Helps in attachment of Platelets to Sub-endothelial tissues 5)Inhibits Fibrinolysis
2 , 4 -Activate in a Multimeric form. -Helps in attachment of Platelets to Sub-endothelial tissues.
D-Methmalonyl-CoA is Converted to ____ by ____ and then to Succinyl-CoA by Methmalonyl Isomerase with ____ as cofactor.
D-Methmalonyl-CoA is Converted to L-Methmalonyl-CoA by Methmalonyl Racemase and then to Succinyl-CoA by Methmalonyl Isomerase with Vit B12 as cofactor.
Choose the FALSE one for Drug metabolism: 1)Conjugation is the first reaction in Biotransformation. 2)Usually the in 1st step substrate becomes water soluble. 3)In the Preparatory Phase, actually reactive intermediates are formed. 4)The conjugated derivatives are usually inactive.
1 is WRONG! Conjugation is actually the second reaction in Biotransformation.
What are the negative and positive regulators of Isocitrate Dehydrogenase:
Positive Regulators: ADP and Ca Negative Regulators: ATP and NADH
True for Tetrahydrofolate reactions: 1)One carbon units carried by Tetrahydrofolate may be derived from Serine, Glycine or Tyrosine. 2)All one carbon units bound by Tetrahydrofolate can be transformed into each other. 3)Methyl Group carried by Tetrahydrofolate is derived from Methionine.
2 All one carbon units bound by Tetrahydrofolate can be transformed into each other.
The E3 subunit of PDH enzyme complex is also part of :
E3 of PDH also in: -alpha-KGDH -BCKADH -Glycine cleavage complex
Two cells cooperate in ovarian production of Estradiol from cholesterol:
Theca interna and Granulosa cells
What is characteristic for Fibrinolysis: 1)Fibrin is degraded by Proteolytic enzymes 2)Cross links between fibrin (FXIIIa job) are not degraded 3)Plasmin is synthesized in proenzyme form. 4)Alpha2 plasmin inhibitor is more efficient if Plasmin is Fibrin bound.
1 , 2 , 3 -Fibrin is degraded by Proteolytic enzymes -Cross links between fibrin (FXIIIa job) are not degraded -Plasmin is synthesized in proenzyme form.
How does PKA regulates Glycogen Synthase?
Phosphorylates and Deactivates it.
In Lactic Acidosis: 1)Elevated Lactate production results in increased pH. 2)Enzyme deficiency of Pyruvate Carboxylase results of Hypperammonemia. 3)Dihydrolipoyl Dehydrogenase enzyme deficiency effects only Glycolysis. 4)Dihydrolipoyl Dehydrogenase enzyme deficiency effects Glycolysis, TCA Cycle, and catabolism of Branched Chain Amino Acids. 5)NaHCO3 alone is a very effective treatment.
2 , 4 -Enzyme deficiency of Pyruvate Carboxylase results of Hypperammonemia. -Dihydrolipoyl Dehydrogenase enzyme deficiency effects Glycolysis, TCA Cycle, and catabolism of Branched Chain Amino Acids.
Cytochrome P450 Enzyme participates in: 1) FA Desaturate System 2) Bile Acid Synthesis 3) Drug Hydroxylation 4) Citrate Cycle 5) Glucocorticoid Synthesis
1) FA Desaturate System 2) Bile Acid Synthesis 3) Drug Hydroxylation 5) Glucocorticoid Synthesis
Low group transfer potential indicates a tendency of the molecule to ___ a group.
Receive a group. For example G6P has Low phosphryl group potential preventing it from releasing Pi .
Insulin activates Glycolysis in the Liver by ___ the F2,6BP concentration.
Increasing
False one for Potassium channels: 1)The K+ channel has an inverted Teepee structure. 2)K+ channels share a conserved P-loop region 3)Na+ is excluded from K+ channel because it is too large. 4)K+ channels have a water filled central cavity.
3 Na+ is excluded from K+ channel because it is too SMALL. electrostatic interactions are no energetically favorable for it’s transport.
How is Platelet activation inhibited in the clinical practice:
Acetylsalicylic acid - > inhibits COX - > No TXA2.
Which enzyme catalyzes the reaction transforming Inosine into hypoxanthine?
Purine Nucleoside Phosphorylase (“PNP”)
What are the two major different Eicosanoids synthesis pathways?
Cyclooxygenase Pathway - Prostaglandins and Thromboxanes Lipoxygenase Pathway - Leukotrienes and Lipoxins.
Which statements are valid for the PGI2: 1)Synthesized from free arachidonate 2)It is released from Phospolipids by PLA2 3)Synthesized in Platelets by Prostacyclin synthase
1 and 3
PGI2 is synthesized from free arachidonate
Synthesized in Platelets by Prostacyclin synthase
(Old name for COX)
True for tPA activation: 1)Fibrinogen stimulates it 2)Fibrin stimulates it 3)Partial degredation of Fibrin stimulates it 4)Carboxypeptidase B stimulates it 5)Some of plasmin fibrin degredation products Stimulates it.
2 , 5 Fibrin , Some Plasmin fibrin degredation products.
10 ml 0.1 Glutamate solution (starting from fully protonated form) is titrated with 0.3 N NaOH in which NaOH ml do you expect buffer formation?
5 ml 15 ml 25 ml
Which one is NOT true: 1)Vmax=Et x Kcat 2)Turnover number is Kcat 3)1 U is 1 Mol substrate/Minute 4)Specificity constant is Kcat/Km.
1 U is 1 Mol substrate per Second.
Which lipids are essential for the normal function of the alveolar Surfactant: 1)Dipalmitoyl-Phosphatadylcholine 2)Oleyl-Palmitoyl-Phosphatadylcholine 3)Cholesteryl-Ester 4)Phosphatadyethanolamine 5)Spingomyelin
1 , 4 Phosphatadyethanolamine and Dipalmitoyl-Phosphatadylcholine are needed for Surfactant.
True for Amylase: 1)Produced in Pancreas and Salivary Glands. 2)Cleaves Alpha 1-4 and 1-6 bonds 3)Function not effected by Gastric pH. 4)Doesn’t Cleave disaccharides 5)Amylopectin is a substrate.
1 , 4 , 5 1)Produced in Pancreas and Salivary Glands. 4)Doesn’t Cleave disaccharides 5)Amylopectin is a substrate.
Which Calcium channel in the Heart is rapidly inactivated?
T-type
Which Amino acid is not a Precursor of Fumarate: 1)Asp 2)Asn 3)Phe 4)Tyr 5)Trp
5 Tryptophan is not a precursor of Fumarate.
FALSE for GABA-A receptors: 1)its activation causes Hyperpolarization 2)It’s a Chloride channel 3)Activation of it could cause insomnia. 4)It can bind Ethanol
Activation of GABA-A receptors could NOT cause insomnia .
Causes of Thrombophillia: 1)Protein C deficiency 2)Antithrombin deficiency 3)FVII deficiency 4)FV resistance against activated protein C (APC resistance. 5)FXI deficiency
1 , 2 , 4 1)Protein C deficiency 2)Antithrombin deficiency 4)FV resistance against activated protein C (APC resistance.
NPC1L1 Function?
Pumps Cholesterol to the Intestinal Epithelial Cells.
In Transamination of Alanine to form Alpha-KG, which co-factor is used?
PLP
Galactosemia cause:
Galactose-1P Uridylyl Transferase or Galactokinase Deficiency
The following fatty acid, in which the indicated carbon is labled with [14C], is fed to an animal. [14C]H3(CH2)9COOH After 30 minutes of Beta oxidation, the label would most likely be recovered in which form: 1)Acetyl-CoA 2)Propionyl-CoA 3)Palmitoyl-CoA 4)Both Propionyl-CoA and Acetyl-CoA.
2 Propionyl-CoA, since this is a Fatty acid with Odd number carbon chain and Beta oxidation starts from Carboxylic end of the FA.
What harmful intermediate will inevitably form in the process of elimination of xenobiotics:
In biotransformation ROS are formed.
True for IP3 receptor (MCQ):
1) Localized on ER and Plasma Membrane
2) it is a Calcium channel
3) it has 4 Calcium binding sites
4) Binds ATP
5) Is activated by Phospholipase C
2 , 4 , 5
*Phospholipase C forms the ligand IP3
*Also not sure if it directly binds ATP but this was the combo
Which weak Andronergic Steroid is synthesized in the fascicular zone of Adrenal Cortex: 1)Dehydroepiandrosterone 2)Corticosterone 3)Progenolone 4)Progesterone 5)Testosterone
1 Dehydroepiandrosterone aka DHEA
Which are positions and configurations of the OH groups in Primary Bile Acids:
OH on 3 , 7 , 12 positions in Primary Bile Acids all in alpha configurations.
Transketolase requires the Coenzyme: 1)Pyridoxal Phosphate 2)Thiamine Pyrophosphate 3)Cobalamin 4)Tetrahydrofolate
2)Thiamine Pyrophosphate (TPP) (Part of the Pentose Phosphate Pathway)
False one for CFTR channels: 1)Transports Cl 2)It is an ABC protein 3)Inhibited by PKA phosphorylation 4)has two transmembrane domains (TMD)
3 CFTR is actually activated by PKA phosphorylation
Product of the reaction catalyzed by the Thymidylate Synthase?
dTMP
Activation of Trypsin?
Enteropeptidase arriving to duodenum cleaves Trypsinogen (Zymogen) to form Trypsin. (Limited Proteolysis)
Which protein binds calcium in Vesicular Synaptic transmission: 1)Synaptotagmin 2)Synaptobrevin 3)SNAP25 4)Syntaxin
1 Synaptotagmin binds calcium in Vesicular Synaptic transmission
Inhibitors of Cyclooxygenase: 1)Docosahexanoic Acid 2)Arachidonic Acid 3)Acetylsalicylic acid 4)Thromboxane
1 , 3 Docosahexanoic Acid and Acetylsalicylic acid
Which of the following is involved in the activation of pancreatic proenzymes:
1) Carboxypeptidase A
2) Enteropeptidase
3) Trypsin
4) Chymotrypsin
5) Pancreatic Lipase
2 , 3
Enteropeptidase arrives to the Duodenum to cleave and activate Trypsin which later cleaves and activates the rest of the Pancreatic Proenzyme Proteases .
What is true about voltage gated Cl- channels structure: 1)Two subunits each creating a pore 2)Two subunits creating a pore together 3)Single polypeptide with two pores 4)Single polypeptide with one pore
1 Two subunits each creating a pore
What of the following statements explains the Relatively specific effect of Strophantin on the Heart? 1)Na-Ca exchanger is found only the Heart 2)Na-K ATPase alpha subunit in heart bind strophantin with the lowest affinity 3)Na-K ATPase alpha subunit in heart bind strophantin with the lowest Km 4)Strophantin Binds to Na-K ATPase intracellularly in the heart.
3 Na-K ATPase alpha subunit in heart bind Strophantin with the lowest Km. Strophantin = Cardiac Glycoside
Which of the following Amino Acids have their Alpha-Amino groups removed by Dehydratase?
Serine and Threonine
Norepinephrine break down to:
MHPG or VMA
What are the Irreversible steps of Glycolysis?
1) F6P to F1,6BP by PFK1 2) PEP to Pyruvate By Pyruvate Kinase 3) Glucose to G6P by Hexokinase
True for ATP sensitive potassium channel: 1)Inhibited by ADP and Activated by ATP 2)Inhibited by ATP and Activated by ADP 3)ATP binds on intracellular Domain 4)ATP binds on extracellular domain
2 , 3 ATP sensitive K+ channel Inhibited by ATP and Activated by ADP, ATP binds on intracellular Domain.
In Activation of PLC : 1)Serpentin receptors are involved 2)cAMP is involved 3)Heterotrimer G proteins are involved 4)DAG is involved
1 , 3 GPCRs (in this case Gq) are G-proteins coupled receptors. Linked to heterotrimeric G proteins and also called Serpentins.
Which are NOT classified as Ketone bodies : 1)Dihydroxyacetone 2)Acetoacetate 3)Beta-Hydroxybutyrate 4)Alpha-Hydroxybutyrate 5)Oxaloacetate
1 , 4 , 5 Dihydroxyacetone, Alpha-Hydroxybutyrate and Oxaloacetate are NOT Ketone bodies.
Which Sentence is NOT valid for Cholesterol overload : 1) Inhibits LDLR expression 2) Affects the Cholesterol Synthesis in the Cells 3)Inhibits HMG-CoA reductase 4) Cause formation of Cholsteryl-Esters by LCAT in the Cells
4) Cause formation of Cholsteryl-Esters by ACAT in the Cells NOT LCAT.
Name the Protein induced by ACTH in the adrenal cortex:
StAR protein or : Steroidgenic Acute Regulatory Protein.
Which steroid hormone is synthesized by 11-Beta-Hydroxylase: 1)Aldosterone 2)Cortisol 3)Testosterone 4)Estradiol 5)Progesterone
2 Cortisol is synthesized from by 11-Beta-Hydroxylase 11-deoxycortisol.
True for vWF: 1)Substrate of Thrombin 2)Secreted from Endothelial Cells 3)Contributes to Aggregation of Platelets 4)Contributes to Adhesion of Platelets 5)Binds to Factor VIII in the circulation
2 , 4 , 5 2)Secreted from Endothelial Cells 4)Contributes to Adhesion of Platelets 5)Binds to Factor VIII in the circulation
Which of the following can be synthesized by plants but NOT by Humans: 1)Palmitate (18;0) 2)Stearate (20:0) 3)Linoleate (18:2) 4)Pyruvate 5)Phosphatydilcholine
3 Linoleate (18:2) is an essential Fatty acid (Omega-6). (the other important one is Linolenate (18:3)- Omega - 3)
Work both in Gluconeogenesis and Glycolysis: 1)Hexokinase 2)Glucose-6-Phosphatase 3)3-phophoglycerate kinase 4)PFK1 5)Pyruvate Kinase
3 Since 3-phosphoglycerate catalyzes a reversible reaction it is working in Glycolysis and Gluconeogenesis both.
Enzymes in De-Novo Synthesis of Pyrimidines: 1)Pyrimidine phosphorybosiltransferase 2)Aspartate Carbamoyltransferase 3)Ornithine Carbamoyltransferase 4)CTP Synthetase
2 , 4 2)Aspartate Carbamoyltransferase 4)CTP Synthetase (3 - Urea cycle , 1 - Salvage)
Product and Substrate of major regulatory enzyme of the cholesterol synthesis pathway:
HMG-CoA reductase: Substrate is HMG-CoA and Product is Mevalonate.
Pick the FALSE statement:
1) If Delta-G is negative the reaction is Exergonic.
2) Irreversible reactions have Delta-G of small value.
3) If Delta-G is Positive the reaction is Endergonic.
4) Exergonic processes are coupled to Endergonic ones
2 Irreversible reactions have Delta-G of LARGE value.
Which of the following compounds will be reduced by Ribonucleotide Reductase: 1)TMP 2)UMP 3)dUDP 4)UDP 5)UTP
4 (Di)Ribonucleotide Reductase reduces: UDP , CDP, GDP and ADP. (dTMP will come from thimydilate synthase reaction)
What is Glycogenin:
The Primer on which new Glycogen chains are synthesized.
True for Kidney Metabolism: 1)PFK1 is active mainly in the Cortex 2)Hexokinase is active mainly in the Medulla. 3)PEPCK activity is associated with the Cortex 4)Acidosis-Induced Glutamate activity localized in cortex. 5)G-6-Pase activity in cortex.
2 , 3 , 5 -> Medulla=Glycolytic and Cortex=Glucogenic. 2)Hexokinase is active mainly in the Medulla. 3)PEPCK activity is associated with the Cortex 5)G-6-Pase activity in cortex.
In anaerobic muscle preparation lactate formed from glucose labeled in C3 and C4 would be labeled in : 1)All three carbon atoms 2)The carboxyl atoms only 3)The carbon carrying the OH only 4)Methyl Carbon only 5)Methyl and Carboxyl Carbons
5 Methyl and Carboxyl Carbons. Remember: Aldolase reaction products are Not symmetrical.
Degradation of cAMP:
1) catalyzed by PDE
2) inhibited by Caffeine
3) Activated by cGMP
4) Catalyzed by Adenylate Cyclase
1 , 2 Catalyzed by PDE inhibited by Caffeine
Which molecule has a lower group transfer potential than ATP: 1)Creatine Phosphate 2)Phosphoenolpyruvate 3)Glucose-6-phosphate 4)1,3Bisphosphoglycerate
Glucose-6-phosphate has a lower group transfer potential than ATP. It is less likely to Donate a phosphate group in comparison to ATP.
Alpha-Ketoglutarate Dehydrogenase complex consists of the following enzymes, coenzymes and prosthetic groups: 1)Dihydrolipoyl succinyltransferase 2)Pyridoxal-5-Phosphate 3)Lipoic Acid 4)Alpha-Ketoglutarate-Decarboxylase 5)Pyruvate Decarboxylase
1 , 3 , 4 1)Dihydrolipoyl succinyltransferase 3)Lipoic Acid 4)Alpha-Ketoglutarate-Decarboxylase
False for Isoenzymes: 1)Catalyze the same reaction 2)Have different structure 3)Always share the same allosteric regulators 4)Can be tissue specific
3 Isoenzymes have different allosteric regulators.
Phosphrylated and Active in the Liver During Starvation: 1)PFK1 2)Glycogen Synthase 3)Pyruvate Kinase 4)Glycogen Phosphorylase 5)Phosphorylase Kinase
4 , 5 Glycogen Phosphorylase and Phosphorylase Kinase
Which of these proteins are activated by Calcium but not by Ca-Calmodulin complex: 1)PFK1 2)RYR 3)Actin-Myosin complex 4)PKC
2 , 4 PKC and RYR can be activate by Ca ion one its own.
False for Oxidative Decarboxylation of Pyruvate: 1)Catalyzed by a large Enzyme Complex in the Cytosol 2)If it happens in anaerobic conditions E2 is not used 3)it is a Substrate level phosphorylation - ATP formed 4)E1 prosthetic group is Biotin
All are false - now for the Truth about PDH: 1)Catalyzed by a large Enzyme Complex in the Mito. 4)E1 Prosthetic group is TPP
True for the mechanism is regulating the synthesis of Testosterone: 1)Cholesterol side chain cleavage is inhibited by cAMP 2)Testosterone induces the release of GnRH from Hypothalamus 3)LH activates Adenylate cyclase in Leydig Cells
3 LH activates Adenylate cyclase in Leydig Cells leading to the expression of 17β-hydroxysteroid dehydrogenase - Testosterone Conversion
Which of the following circulatory elements will decrease the affinity of hemoglobin for oxygen: 1)High 2,3 BPG 2)High pH 3)High CO2 4)Low CO2 5)High [H+]
1 , 3 , 5 High 2,3BPG, CO2 and [H+] will all decrease the affinity of hemoglobin for oxygen.
Correct the order by energy output (Highest on Left): 1)Glucose>Alanine>Palmitate 2)Palmitate>Alanine>Glucose 3)Palmitate>Glucose>Alanine 4)Glucose>Palmitate>Alanine 5)Alanine>Glucose >Palmitate
3 Palmitate>Glucose>Alanine 108 ATP > 34 ATP~ > 7ATP~
True for Hereditary Fructose Intolerance: 1) Cause is inadequate function of Aldolase B 2) Accompanied by Hypoglycemia 3) Results in Liver Damage 4) Glycogenolysis is Increased 5) Results in the accumulation of of F1P
1 , 2 ,3 ,5 1) Cause is inadequate function of Aldolase B 2) Accompanied by Hypoglycemia 3) Results in Liver Damage 5) Results in the accumulation of of F1P
Are these two sentences true? Is there any connection? 1)RBCs form large amounts of 2,3 bisphosphoglycerate 2)Glycolysis in RBCs yield less ATP than in other cells.
Both 1 and 2 are True. Because RBCs have a shunt reaction that (sometimes) produces 2,3BPG instead of 1,3BPG Glycolysis in them results in production of less ATP.
What factor is involved in the efflux of Calcium from Mitochondria: 1)Ca-uniporter 2)IP3-receptor 3)Na-Ca exchanger 4)T-Channel 5)Rynodine receptor
3 Na-Ca exchanger
Cortisol formation from Progenalone - CYPs:
1)17 Hydroxylase 2)21 Hydroxylase 3)11 Hydroxylase (3-beta-HSD also after 1 but not CYP)
An example for an Eicosanoid hormone is : 1)Testosterone 2)Epinephrine 3)Thyroxine 4)Thromboxane 5)Retinoic Acid
4 Thromboxane
Choose on true statement for FA Activation : 1)UDP Acids are formed 2)Requires ATP and CoA 3)Requires Carnitine 4)CoA group comes from Malonyl - CoA 5)Phosphorylation with ATP
2 Requires ATP and CoA
True for Malignant Hyperthermia: 1)It is characterized by muscle rigidity 2)It is the result of abnormal CNS Thermoregulation 3)It is the result of RYR mutation 4)Can be treated with calcium channel blockers 5)It is accompanied by intensive Lactate production in the Muscles
1 , 3 , 5 are True for Malignant Hyperthermia.
Pituitary hormone promoting the conversion of cholesterol to Progenenolone in the Adrenal Cortex:
ACTH - Adrenocorticotropic Hormone
Which are valid for Bile acids:
1) In its synthesis the Cholesterol side chain is oxidized
2) In its synthesis carbon atoms 7 and 12 are methylated
3) The secondary bile acids are produced from primary ones through deconjugation and dehydroxylation of 7th Carbon atom
4) Glycocholic and Taurocholic are primary bile acids
5) Litocholic is formed from Glycocholic by bacteria in colon
1 , 3 , 4 are valid for Bile acids
1) In its synthesis the Cholesterol side chain is oxidized
3) The secondary bile acids are produced from primary ones through deconjugation and dehydroxylation of 7th Carbon atom
4) Glycocholic and Taurocholic are primary bile acids
What is a substrate for CYP11: 1)Aldosterone 2)Testosterone 3)Progesterone 4)Corticosterone
4 Corticosterone
High group transfer potential indicates a tendency of the molecule to ___ a group.
Donate a group. For example PEP has High phosphryl group potential allowing it to aid in ATP formation in donating Pi.
Tryptophan derivatives: 1)Lys 2)Acetoacetyl-CoA 3)Nicotinamide 4)Ala 5)Serotonin
2 , 3 , 4 , 5 -Acetoacetyl-CoA -Nicotinamide -Alanine -Serotonin
Desaturase system requires all of the following EXCEPT: 1)O2 2)Cyt B5 3)ATP 4)NADPH
3 ATP is not needed
3 ways for Oxidation of Ethanol? Location of each?
Alcohol Dehydrogenase - Cytosol CYP2E1 - SER Catalase - Peroxisome
Which one is true for - Glutamate->Alpha-KG reaction: 1)Requires ATP 2)Doesn’t require co-factors 3)Accompanied by ATP hydrolysis catalyzed by the same enzyme 4)Catalyzed by GDH 5)Is a reductive deamination
4 GDH - Glutamate Degydrogenase Glu+H20+NAD(P)+ ->KG+NH4+NAD(P)H
Which steroid synthesis pathway doesn’t involve 21-hydroxylation: 1)Aldosterone 2)Cortisol 3)Testosterone 4)Progesterone
3 , 4 Synthesis of Testosterone and Progesterone doesn’t require 21-Hydroxylation.
What Enzyme of the TCA cycle forms GTP?
Succinyl CoA synthetase
False for Acetylcholine: 1)Synthesized by Choline-acetyltransferase 2)De-Novo choline synthesis is carried out by Neurons. 3)There are High and Low affinity Cholin transporters on Neurons 4)Acetylcholine is degraded by Acetylcholinesterase.
2 De-Novo choline synthesis is carried out is not happening in the Neurons therefore they have High and Low affinity Cholin transporters for reuptake.
Select the True statements: 1)Glycogen Phosphorylase is more active in its phosphorylated form. 2)Glycogen dephosphorylase is more active in its phosphorylated form. 3)Glycogen Synthase is more active in its phosphorylated form. 4)Glycogen Synthase is more active in its dephosphorylated form. 5)Glycogen Synthase is more active in its phosphorylated form and Dephosphorylated.
1 , 4 1)Glycogen Phosphorylase is more active in its phosphorylated form. 4)Glycogen Synthase is more active in its dephosphorylated form.
The enzyme that trasforms UDP-Galactose to UDP-Glucose is:
an Epimerase
Thymidylate Synthase: Substrate , Product, Co-Factor, Inhibitor.
S) dUMP P) dTMP Cofactor is Tetrahydrofolate(-Methylene) , Inhibitor is Methotrexate
Which is NOT an Intermediate of the Synthesis of Lansterol from Acety-CoA: 1) Isopentyl pyrophosphate 2) Beta-Hydroxy-Beta-MethylGlutaryl-CoA 3) Beta- Hydroxybutyrate 4) Mevalonate
3) Beta Hydroxybutyrate is just a pathetic Ketone Body.
White Adipocytes in Well-Fed State: 1)HSL digests VLDL and Chylomicrons 2)LPL is inactive 3)Glycolysis produces NADH for the production of Phophoglycerate 4)Triacylglycerol is deposited in lipid droplets 5)High rate of Glucose influx into them.
3 , 4 , 5 are true for White Adipocytes in Well-Fed State: Glycolysis produces NADH for the production of Phophoglycerate. Triacylglycerol is deposited in lipid droplets .High rate of Glucose influx into them.
Are these two sentences true? Is there any connection? 1)Rate limiting step of urea cycle is CPS 1. 2)Increasing N-Acetylglutamate concentration will enhance urea synthesis.
Both are True. Because Rate limiting step of urea cycle is CPS 1 and N-Acetylglutamate is its allosteric activator - Increasing N-Acetylglutamate concentration will enhance urea synthesis.
What are the Obligate Glucose organs?
1)Brain 2)Renal Medulla 3)Testis 4)Lens and Cornea
Patients with deficiency of Carbamoyl-Phosphate Synthatase 1 and Ornithine transcarbamoylase are treated with Sodium Benzoate and Sodium Phenylacetate. Why?
Benzoate conjugates with Gly and removes one Nitrogen. Phenylacetate conjugates with Gln and removes two Nitrogen atoms. The products are released into urine.
The Allosteric activator of Pyruvate Carboxylase: 1)Acetyl-CoA 2)Oxaloacetate 3)CoA 4)ATP 5)NADH
1 Acetyl-CoA
Which of the following statements are true for Urea Cycle?
1) TCA cycle internediate is formed in it.
2) Its enzymes are located either in the cytosol or Mitochondria.
3) Condensation of Citruline and Glutamate requires ATP.
4) Synthesis of Urea costs hydrolysis of three group transfer potential bonds.
1 , 2 , 4
In the Urea Cycle Fumarate is formed which is a TCA cycle internediate. Its enzymes are located either in the cytosol or Mitochondria. (3ATPs cost)
Mcardle Disease: Cause and Symptoms?
Cause : Muscle Glycogen Phosphorylase Deficiency Symptoms: Poor exercise tolerance (Normal Blood glucose level)
Recognize the enzyme complex from these lines: Factor Xa hydrolyzes two peptide bonds. Vitamin K antagonist inhibit its formation. Factor Xa efficiency increases in it by orders of magnitude.
Prothrombinase Complex
Which lipoprotein carries Cholesterol to the extra-hepatic tissues:
1) VLDL
2) IDL
3) LDL
4) HDL
5) Chylomicron
3
LDL carries Cholesterol to the extra-hepatic tissues.
Correct order for enzymes of Ketone Bodies Synthesis: 1)HMG-CoA Lyase 2)Thiolase 3) 3(Beta)-hydroxybutyrate dehydrogenase 4)HMG-CoA Synthase
- > Thiolase - > HMG-CoA Synthase - > HMG-CoA Lyase - > 3(Beta)-hydroxybutyrate dehydrogenase
Phosphorylation of Glucose (MCQ): 1)Requires ATP 2)Catalyzed by Cell Specific Kinases 3)Catalyzed by Hexokinase 4) It is Reversible
1 , 2 Requires ATP Catalyzed by Cell Specific Kinases
Select one true statement: 1)Plasma membrane is not permeable for Na 2)Increasing K intracellularly activates Na/K ATPases 3)Na/K ATPases decrease the extracellular K 4)Na/K ATPases function requires the Na electrochemical gradient.
3)Na/K ATPases decrease the extracellular K
What is the difference in the Isoenzyme regulation of PFK2 by PKA in the Skeletal Muscle in comparison to other tissues? Why?
There is NO phosphorylation of the Skeletal Muscle Isoenzyme of PFK2 by PKA - Due to Alternative Splicing. Liver type gets phosphorylated and Inactivated by PKA. Heart type gets phosphorylated and Activated by PKA.
Which are the One Carbon derivatives of Tetrahydrofolate?
1) Methyl -Tetrahydrofolate 2)Methylene -Tetrahydrofolate 3)Methenyl -Tetrahydrofolate
Disease caused by K+ voltage gated channel mutation: 1)Meysthenia 2)Myotonia 3)Epilepsy 4)Cystic fibrosis 5)Long QT syndrome
5 Long QT Syndrome
Choose the Correct Statements: 1) Nascent HDL doesn’t contain Cholesteryl Esters 2) TAGs are transferred from VLDL to HDL 3) Cholesterol Are transferred from VLDL to HDL 4) Hepatic Lipase degrades TAGs in HDL 5) Liver takes up HDL-derived Cholesterol in LDL form.
1) Nascent HDL doesn’t contain Cholesteryl Esters 2) TAGs are transferred from VLDL to HDL 4) Hepatic Lipase degrades TAGs in HDL
PDH Cofactors:
1)TPP 2)Lippoate 3)CoA 4)FAD 5)NAD
A reaction of Glyceraldehyde-3-P with Fructose-6-P catalyzed by Transketolase (PPP) will form?
Erythrose-4-P and Xylulose-5-P
Which are true for AMPK in the muscle : 1)Phosphorylates glycogen synthase kinase 2)Enhances the rate of glycolysis 3)Increases the rate of protein synthesis 4)One target of it is Acetyl-CoA Carboxylase 5)It will increase indirectly the entry of FA to Mitochondria.
4 , 5 4) One target of it is Acetyl-CoA Carboxylase 5) It will increase indirectly the entry of FA to Mito. (Phosphorylates glycogen synthase kinase only in Liver)
factors of CTP Synthesis: 1)NADH 2)FADH2 3)Mg2++ 4)Acetyl-CoA 5)ATP
3 , 5 ATP and Magnesium ion
When Insulin level in blood rises which enzyme activity elevates: 1)G6PD 2)Malic Enzyme 3)Pyruvate Carboxylase 4)PEPCK 5)Citrate Lyase
1 , 2 , 5 Insulin is Pro-FA Synthesis, it is Lipogenic. G6PD and Malic Enzyme helps form NADPH Citrate Lyase helps form more Acetyl-CoA - Lipogenic.
Choose the Correct statement for Eicosanoid synthesis: 1)Thrombaxanes are produced from Arachidonate via the “linear path”. 2)Early step of the Pathway is inhibited by Aspirin 3)Aspirin acts by blocking the synthesis of Arachidonate 4)Plants can synthesize Leukotrines but Humans cant.
2 Early step of the Eicosanoid synthesis pathway is inhibited by Aspirin.
Glutathione is a(n): 1)Product of Glutamate and Methionine 2)Tripeptide of Glycine, Glutamate and Cysteine 3)Enzyme essential in the synthesis of Glutamate 4)Methyl donor group in many synthesis pathways
2 Tripeptide of Glycine, Glutamate and Cysteine
In what metabolic Situation will the Following process be active continuously: 1) Glycogenolysis 2) Glutamine Synthesis 3) Ketone Bodies Synthesis
Starvation
PGI2 is formed from?
Arachidonic Acid
How do Platelets aid Thrombus formation:
1) ADP Secretion
2) With their Phospholipid surface binding coagulation factors
3) TXA2 Secretion
4) with Secretion of vWF
5) PAI-1 Secretion
1 , 2 , 3 , 4, 5
1) ADP Secretion
2) With their Phospholipid surface binding coagulation factors
3) TXA2 Secretion
5) PAI-1 Secretion
4) with Secretion of vWF (Activated platlets are able to screte it!)
Which Amino Acids are modified in Collagen, which Vitamin is Needed for the Modification?
Proline and Lyine - Hydroxylation
Vitamin C
Scurvy is happening when there is no Vit C
Amino acids of Catalytic triad of Serine Protease:
His , Ser , Asp
Na - H Exchanger :
Where is it found?
Function - What goes in and out?
pH will ____ if it is inhibited.
Located in the Intercalated cells of collecting ducts of kidney.
H- Out and Na - In.
pH will rise if it is inhibited.
Regulators of HMG-CoA Reductase:
- Statins
- Cholesterol
- AMPK
Reaction of PEPCK:
Substrates: Oxaloacetate and GTP
Products: PEP, GDP and CO2
Effects of Strophantine:
Na/K ATPase Inhibition (Partial) :
Leads to Na/Ca exchanger reversal and therefore to Increase in Ca intracellularly -
Increased heart muscle contratillity.
Acetylcholine-Esterase Inhibitor
DFP
5-alpha-Reductase reaction:
Substrates: Testosterone + NADPH H+
Products: Dihydrotestosterone + NADP+
PRPP Synthase reaction:
Substrates : Ribose-5-P + ATP
Products : PRPP +AMP
Effect of AMPA activation on NMDA:
When AMPA receptors are stimulated, they open and depolerize. The cell depolarization causes the removal of Mg2+ ion that was inhibiting the NMDA.
This causes Activation of NMDA.
Mechanism of Ecstasy:
▪ Binds and inhibits noradrenaline transporters, dopamine transporters and serotonin transporters (highest affinity).
▪ Serotonin release and subsequent depletion.
▪ Inhibition of tryptophan hydroxylase and monoamine oxidase (effect on metabolites synthesized in the periphery).
▪ Dopamine release and subsequent depletion.
▪ Generation of toxic free radicals - neurodegeneration.
▪ Cardiovascular and sympathetic effects (tachycardia, arrhythmia, vasoconstriction).
▪ Increased body temperature.
▪ Hyperactivity.
Select the true statments:
1) Formation of Tyr is an essential step in the metabolism of Phe
2) Phenylalanine may lose its amine group through tramsamination
3) Carbon skeleton of Phe yeilds Acetoacetate
3) Carbon skeleton of Phe yeilds HMG-CoA
1 , 2 , 3
1) Formation of Tyr is an essential step in the metabolism of Phe
2) Phenylalanine may lose its amine group through tramsamination
3) Carbon skeleton of Phe yeilds Acetoacetate
Lipoproteins that are digested by Hepatic Lipase:
IDL
HDL2
List at list two signs of LPL deficiency:
Hypertriacylglyceremia
Pacreatitis
Xanthomas
Lipemia
Hepatosplenomegally
List at least two functions on Carnitine
FA transport into Mitochondria
Chort chain acyl-CoA export from mitochondria
Maintainance of free CoA-SH level
A - Urea
B - Glutamate
C - Cholesterol
D - Aspartate
E - Arginine
F - Carbamoyl Phosphate
Conversion from Cholesterol to Pregnenolone:
Enzyme and Co-Factors
Substrates: Cholesterol + 3 NADPH + 3 H+ + 3 O2
Pregnenolone + 4-methylpentanal + 3 NADP+ + 3 H2O
By Cholesterol Side Chain Cleavage Enzyme
Which of the following statements is True:
1) Cyclooxygenase activity needs organic epoxide initiators
2) Steroid hormones contribuit to biosynthesis of COX
3) Tyr-385 is in Ionized form in COX protein
4) COX activity needs an organic peroxide activity
5) The active COX is monomeric
3
Tyr-385 is in Ionized form in COX protein
Which of the following reactions with Folic acid (F) are Reversible:
1) N10-N5-Methylene THF to N5-Methyl-THF
2) N10-FormyL-THF to N10-N5-Methenyl THF
3) N10-N5-Methenyl THF to N10-N5-Methylene THF
4) N5-Methyl-THF to THF
2 , 3 Are Reversible
- N10-FormyL-THF to N10-N5-Methenyl THF
- N10-N5-Methenyl THF to N10-N5-Methylene THF
Which two “kinds” of Amino acids share a common transporter on the Blood Brain Barrier?
BCAAs share the same transport protein into the brain with aromatic amino acids (Trp, Tyr, and Phe).
