Quiz 1 LOs Flashcards by Deleted Deleted

What is the rate limiting enzyme of glycolysis?
What 2 molecules activate it?
What 2 molecules inhibit it?

PFK-1
ACTIVATE: AMP, F-2,6-BP

INHIBIT: ATP, citrate

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Which of the following glucose transporters is located in the liver with the lowest affinity, and which is regulated by insulin?

GLUT1
GLUT2
GLUT3
GLUT4

GLUT2 is in liver with lowest affinity

GLUT4 is regulated by insulin

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Pyruvate kinase is a major regulated step in glycolysis. What 2 molecules stimulate activation, and what 3 molecules inhibit its activity?

Note: Pyruvate kinase works and you’re “in”, but when it’s off “GAA”

ACTIVATE: Insulin, F-1,6-BP

INHIBIT: Alanine, ATP, Glucagon

Note: Pyruvate kinase works and you’re “in”, but when it’s off “GAA”

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Which of the two hormones is associated with dephosphorylation?

A. Glucagon
B. Insulin

Insulin

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Taurus’ are Pretty Fucking Kind, but Tarui disease is not. PTs present with exercise induced cramps, hemolytic anemia, high bilirubin and jaundice. Teuri disease is caused by a deficiency in what major enzyme of glycolysis?

PFK-1

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T/F: It seems like insulin and phosphatases is always vs. glucagon and cAMP/PKA

True

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Pyruvate can be converted to alanine through what two metabolic processes?

Gluconeogenesis

Urea cycle

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About 95% of glycolysis related anemias are associated with defects in what enzyme?

Pyruvate kinase

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What are two major clinical markers for hemolytic anemia?

A. Lactate dehydrogenase, conjugated bilirubin
B. Pyruvate kinase, PFK-1
C. Lactate dehydrogenase, unconjugated bilirubin
D. None of the above

Lactate dehydrogenase, unconjugated bilirubin

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Fanconi-Bickel syndrome is a “TWO-NAME SYNDROME”, with a lot of words to TRANSPORT. Presentation includes hepatosplenomegaly, failure to thrive, and resistant rickets. What deficiency is causes this two-name syndrome?

GLUT2 defect that prevents transport of glucose, galactose, and fructose to be transported

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Which of the following, is an activator for all of the major regulatory steps of gluconeogenesis that include the following enzymes: Pyruvate carboxylase, PEP carboxykinase, F-1,6-Biphosphatase, and Glucose-6-phosphatase?

A. AMP
B. Cortisol
C. Citrate
D. ADP

Cortisol

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What is the rate limiting enzyme of gluconeogenesis?
What are the 2 aCCtivators?
What are its 2 inhibitors?

Fructose-1,6-biphosphatase
ACTIVATORS: Citrate, Cortisol

INHIBITORS: AMP, F2,6BP

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What are the only 3 activators of PEP carboxykinase that stimulate its activity in gluconeogenesis?

Cortisol
Glucagon
Thyroxine

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What are the 2 activators of pyruvate carboxylase and its only ADept inhibitor as it acts in gluconeogenesis?

ACTIVATOR: Cortisol, Acetyl CoA

INHIBITOR: ADP

NOTE: pyruvate carboxylase has an ADept inhibitor

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If F2,6BP activates PFK-1 in glycolysis then it makes sense that F2,6BP inhibits what enzyme in gluconeogenesis?

Fructose-1,6-biphosphatase

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Which of the following enzymes is the only one to be found in the mitochondria and utilizes biotin (B7)?

A. PEP carboxykinase
B. Fructose-1,6-biphosphatase
C. Glucose-6-phosphatase
D. Pyruvate carboxylase

Pyruvate carboxylase

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Tarui disease is caused by a deficiency in PFK-1. What other disease is similar to Tarui disease in gluconeogenesis?

Fructose-1,6-biphosphatase deficiency and Tarui disease present similaraly

Lactic acidosis, hypoglycemia

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Explain how glucose is made into fructose in cells that have sorbitol dehydrogenase in the Polyl pathway. Include intermediates and enzymes used.

Glucose + Aldose reductase –> sorbitol + sorbitol dehydrogenase —> fructose

Cells lacking sorbitol dehydrogenase: Kidney, retina, schwann cells

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Fructose w/ _________ makes F6P, and enters in glycolysis. While fructose with _______ makes F1P, skipping major regulatory step and entering glycolysis at intermediate Glyceraldehyde 3 phosphate

Hexokinase

Fructokinase

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In fructose metabolism, what two enzymes bypass the major regulatory step of glycolysis?

Fructokinase

Triose Kinase

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Galactosemia has non-classical and classical versions depending on the deficinent enzyme. What is the deficient enzyme in either version that leads to the buildup of galactose or galactitol causing cataracts?

Classical: GALT/glacatose 1P uridyltransferase

Non-classical: Glactokinase

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T/F: Galactose is one step away from Galactitol via aldolase reductase

True

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What is the rate limiting enzyme of the PPP?

Glucose-6-phosphate dehydrogenase

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Which of the following is the likely result with GSD 0? Bonus: what enzyme is deficient?

A. Long chains with few branches
B. Short chains with many branches
C. Free glucose unable to be converted to glycogen
D. None of the above

Free glucose unable to be converted to glycogen

Enzyme: Glycogen synthase (rate limiting enzyme)

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Which of the following is the likely result with Andersen disease (GSD IV)? What enzyme is deficient A. Long chains with few branches B. High number of short branches C. Free glucose unable to be converted to glycogen D. None of the above

Long chains with few branches Enzyme: Glucosyl (4:6) transferase

What is the rate limiting enzyme of glycogenolysis and glycogenesis?

Glycogenesis: Glycogen synthase Glycogenolysis: Glycogen phosphorylase

Which of the following is the likely result with Cori disease (GSD III)? What is the deficient enzyme? A. Long chains with few branches B. High number of short branches C. Free glucose unable to be converted to glycogen D. None of the above

High number of short branches a-1,6-glucosidase

In terms of phosphorylation, which form of glycogen synthase is active and which form of glycogen phosphorylase is active?

DEphosphorylated glycogen synthase is active Phosphorylated glycogen phosphorylase is active

T/F: Glucagon does not act on the muscle

True

ATP citrate lyase is the enzyme responsible for converting citrate back to acetyl CoA and OAA once out in the cytosol in FA synthesis. What are citrate lyase's 2 activators, and what are the 2 inhibitors?

ACTIVATORS: Glucose, Insulin INHIBITORS: PUFA, leptin

T/F: Oxaloacetate is unable to enter and exit mitochondria directly

True

In fatty acid synthesis, which of the following acts as an inhibitor in every major phase? A. PUFA B. Leptin C. Insulin D. Glucagon

PUFA

T/F: Carboxylase enzymes generally utilize biotin as a cofactor

True

What is the rate limiting step and enzyme in fatty acid synthesis?

Acetyl CoA --> Malonyl CoA Acetyl-CoA carboxylase

The presence of malonyl coA inhibits the function of what rate limiting enzyme in fatty acid degredation, in order to prevent them from occuring at the same time?

Carnitine acyl transferase

Phase III of fatty acid synthesis is chain formation where 2carbon units are added to the fatty acyl chain in 7 reactions to form palmitate. What is the name of the enzyme complex that carries this out?

Fatty Acid Synthase Complex

Fatty acid synthase is a complex of 2 identical dimers made up of 7 enzymes and what additional protein with a flexible arm?

Acyl Carrier protein

What 2 hormones/hormone types stimulate the activity of Fatty Acid Synthase Complex?

Insulin | Glucocorticoid hormones

Because the brain requires longer chain fatty acids (C18-24), it is necessary for palmitate to be lengthened. This addition can only happen in 2 different locations, and each use their own carbon donor plus NADPH for reducing power. What are the 2 locations where this occurs, and what are their respective carbon donors?

Smooth ER uses Malonyl CoA | Mitochondria uses Acetyl CoA

What are the 4 human desaturases and where do they each present a new double bond?

delta4: 4-5 delta5: 5-6 delta6: 6-7 delta9: 9-10

TAGs are made in through de novo synthesis in all of the following locations except for which, which is where dietary TAGs are processed? A. Hepatocytes B. Adipocytes C. Intestinal cells D. None of the above

Intestinal cells

What is the name of the lipoprotein that contaiins apolipoproteins and other lipids synthesized from the small intestines? These lipoproteins later enter the lymphatic system through the thoracic duct. A. Chylomacroons B. VLDLs C. LDLs D. Chylomicrons

Chylomicrons

In the de novo synthesis of TAGs made in the liver glucose and glycerol combine to form glycerol-3-phosphate. This glycerol-3-phosphate is used as the backbone and combined with FFAs to form TAGs. These TAGs are packaged into lipoproteins that are called: A. Chylomacroons B. VLDLs C. LDLs D. Chylomicrons

VLDLs

T/F: TAG synthesis in adipocytes is promoted by excess carbohydrates and fats

True

De novo synthesis of TAGs in adipose tissue utilizes what enzyme that combines chylomicrons and VLDLs?

Capillary Lipoprotein Lipase

The breakdown of TAGs involves the work of 3 major lipases. What are their names in the order in which they are used?

1. Hormone Sensitive Lipase 2. Lipoprotein lipase 3. Monoacylglycerol lipase

Unlike short and medium chain FAs, long and very long chain FAs cannot diffuse into the mitochondria and must be actively transported. What is the name of the transporter responsible for shuttling the LCFA and VLCFA into the mitochondria?

Carnitine shuttle

What is the rate limiting enzyme of the carnitine shuttle during fatty acid oxidation? What is it inhibited by

CArnitine palmitotransferase I Inhibited by Malonyl CoA

Ketone bodies are water-soluble, acidic compounds that are only produced in the liver. What are the names of 3 ketone bodies?

Acetoacetate B-hydroxybutyrate Acetone

What are the 3 purposes of nutrition?

1. Promote growth and development 2. Provide energy 3. regulate metabolism

Which of the following proteins is stabilized through hydrophobic interactions with the membrane? A. Integral membrane proteins B. Peripheral proteins C. Lipid anchored proteins D. None of the above

Integral membrane proteins

Which of the following proteins is loosely bound to membrane through electrostatic interactions? A. Integral membrane proteins B. Peripheral proteins C. Lipid anchored proteins D. None of the above

Peripheral proteins

Lipid anchored proteins are tethered to the plama membrane through which of the following interactions? A. Electrostatic B. Hydrophobic C. Covalent D. Ionic

Covalent

All of the following phospholipids are normally found in the outerleaflet except for which of the following which is only found during apopotosis? A. Phosphatidylcholine B. Glycolipids C. Sphingomyelin D. Phosphotidylserine

Phosphotidylserine

Which of the following diseases leads to an accumulation of sphingomyelin in the lysosomes of the liver, spleen, CNS, or bone marrow? What is the deficient enzyme? A. Fanconi-Bickel syndrome B. Niemann-Pick disease C. Andersen Disease D. Cori disease

Niemann-Pick disease deficient in Acid Sphingomyelinase which breaks down sphingomyelin into ceramide and phosphorylcholine

During blood transufsions why is it important to cross match? In other words what are you ensuring doesn't interact between the donor and recipient?

Cross-matching is necessary to ensure the donor's blood antigens doesn't interact with the recipients antibodies in the plasma

In terms of ABO blood system, antibodies are found in the ______ while antigens are found in the _____.

plasma | RBC surface

In order to be a universal donor, what is required of your blood. What is required for a universal acceptor?

Universal donors have no blood group antigens - like Type O w/ H antigen Universal acceptors have no antibodies in their plasma - like Type AB

A patient is diagnosed with advanced liver cirrohsis, and another patient with Beta-lipoproteinanemia. Oddly enough, you notice high levels of excess free cholesterol in the blood. Which of the following issues might you look out for when analyzing the blood further? ``` A. Spur cell anemia B. Neimann-pick disease C. Acanthocytes D. All of the above E. A and B F. A and C ```

F. Spur cell anemia Acanthocytes

A patient presents with renal cholic (abdominal pain associated with kidney stones). PT comes back with a positive nitroprusside test and you diagnose them with Cystinuria. If you were to collect samples of crystals passed by this patient, what might you find they are made of?

Dimeric AA: Cystine Dibasic AAs: Ornithine, Lysine, Arginine CORK

PT presents with cerebellar ataxia, nyastygmus, photodermatitis, and photosensitivity. You record low levels of melatonin, serotonin, and niacin. What is the most likely disease, and what AA is likely not being transported?

Hartnup disease | Tryptophan: an important precursor for serotonin, melatonin, niacin

PT presents with CHF, and you wish to better control this. You select a drug that inhibits the Na/K ATPase that would lead to an increase in intracellular [Na] and impair the secondary NCX which increase [Ca] causing a stronger contraction in cardiac muscle. What is the name of the drug you most likely selected?

Digoxin | Ouabain

T/F: Phosphatase removes a phosphate while phosphorylase is a type of phosphotransferase that adds an additional phosphate group originally from an inorganic compound

True

In order to establish a proton gradient protons must be pumped from the ______ to the ________. This is done through the movement of electrons through the complexes

Matrix (low) | Inner membrane space (high)

When the transfer of electrons is inhibited in the OxPhos 3 things happen. Which of the following is not one of them? A. Decrease in proton pumping B. Decrease in proton gradient C. Increase in proton pumping D. Inhibition of ATP synthesis

Increase in proton pumping

Which of the following occurs when ATP synthase is uncoupled from ETC as seen in hybernating animals? ``` A. Proton leakage back into matrix B. Inhibition of ATP synthase C. Acceleration of TCA and e- transfer to O2 D. Heat production E. All of the above F. All but C ```

All of the above

All of the following is true of the malate-aspartate shuttle except which of the following that is true of the glycerophosphate shuttle? What change would you make to make them all correct? A. Operates in heart, liver, kidneys B. Generates FADH2 in the inner mito-membrane C. Allows entry of oxidant at Complex I D. All the above are correct

Generates FADH2 in the inner mito-membrane Malate-aspartate shuttle generates NADH in the mitochondrial matrix

All of the following is true of the glycerophosphate shuttle except which of the following that is true of the malate-aspartate shuttle? What change would you make to make them all correct? A. Operates in brain and muscle B. Generates FADH2 in the inner mito-membrane C. Allows entry of oxidant at Complex I D. All the above are correct

Allows entry of oxidant at Complex I Glycerophosphate shuttle allows entry of FADH2 at CoQ

An excess in citrate favors which of the following processes? A. Aerobic glycolysis (pyruvate --> acetyl CoA) B. TCA C. Non-oxidative glycolysis (pyruvate--> lactate) D. Activity of PDC

Non-oxidative glycolysis (pyruvate--> lactate)

Which of the following peptidases would clip at the end of a peptide at the C terminus? A. Aminopeptidase B. Carboxypeptidase C. Endopeptidase D. Enteropeptidases

Carboxypeptidase

Which of the following peptidases is responsible for cleaving and activating zymogens in extracellular environment? A. Aminopeptidase B. Carboxypeptidase C. Endopeptidase D. Enteropeptidases

Enteropeptidases

What AAs are ketogenic only, and which are both ketogenic and glucogenic?

Ketogenic only: KL BOTH: WIFTY

Patients with MSUD are likely to have what AA found in thier urine?

Branched Chain AA Treated with thiamine (B1)

PT presents with urine of a musty smelling odor. Analysis shows elevated levels of phenylactate and phenylacetate which are known to block neurotransmission and myelin formation. PT is diagnosed with PKU (Phenylketonuria). What AA is converted erroneously to cause this issue. What AA can be used to treat this issue to supplement the poorly processed AA?

Phenylalanine Tyrosine PKU is caused by defective activity og phenylalanine hydroxylase

PLP is needed in transaminase or aminotransferases and is the active form of which of the following B vitamins? A. B1 B. B2 C. B6 D. B12

T/F: Phenylalanine is converted to Tyrosine through the activity of phenylalanine hydroxylase

True

In order for Tryptophan to make niacin, which of the following vitamins is needed? A. B1 B. B3 C. B6 D. B12

B6 NOTE: B3 is niacin

Melanin is a product of which of the following AAs? A. Threonine B. Tyrosine C. Tryptophan D. None of the above

Tyrosine Dopamine, norepinephrin Thyroid hormones Melanin

Serotonin and melatonin are products of which of the following AAs? A. Threonine B. Tyrosine C. Tryptophan D. None of the above

Tryptophan

THe goal of the urea cycle is to remove nitrogen in the form of ammonia. In the brain ammonia is removed as what two AAs?

Glutamate | Glutamine

thiamine

riboflavin

niacin

Pantothenic acid

Pyridoxine

Biotin

Folic acid

B12

Cobalamin

Vitamin C

Ascorbate

What are the 4 fat soluble vitamins

ADEK

BeriBeri has two forms dry and wet. Deficiency in what vitamin leads to BeriBeri? Describe each form briefly.

Thiamine deficiency (B1) Dry: Muscle wasting and partial paralysis Wet: Peripheral edema and cardiac failure

Accumulation of sorbitol causes cataracts

True

A deficiency in what enzyme impairs the breakdown of medium chain FAs, often leading to secondary carnitine deficiency. The number of C8 fatty acids accumulate in the liver impairing urea cycle and increasing ammonia levels.

Medium chain acyl CoA dehydrogenase

The degredation of very long chain FAs occurs in what cellular location and utilizes what enzyme in the first step? This enzyme is specific to the organelle

Peroxisome Acyl-CoA oxidase

Uracil replaces what pyrimidine base in RNA?

Uracil replaces Thymine

All of the following are true of xanthine oxidase, except for which of the following that is true of adenosine deaminase? A. Converts hypoxanthine to xanthine B. Target for gout treatment C. Converts xanthine to uric acid D. Excess leads to hemolytic anemia, and deficiency leads to SCID

Excess leads to hemolytic anemia, and deficiency leads to SCID NOTE: Adenosine deaminase-performs an irreversible hydrolytic deamination making adenosine to inosine

HGPRT is able to generate which of the following purines in the purine salvage pathway, while APRT is able to generate what? A. AMP B. IMP C. GMP

HGPRT: IMP and GMP APRT: AMP

T/F: On pyrimidine synthesis the rate limiting step is the formation of carbomoyl aspartate

True

Transaminases transfer an amino group to an a-ketoacid and are coupled with what co-enzyme? What B vitamin is the coenzyme derivative of?

PLP-pyridoxyl-5-phosphate B6

Which of the following enzymes is used to remove the NH4 from glutamine creating glutamate? A. Glutaminase B. Glutamine synthase

Glutaminase

Which of the following enzymes is used to add an ammonia to glutamate to make glutamine? A. Glutaminase B. Glutamine synthase

Glutamine synthase

What is the name of the enzyme responsible for removing the ammonia from Glutamine in the brain?

Glutamine synthase

Removal of excess NH4 from the muscle requires what enzyme? A. Glutaminase B. Glutamine synthase C. Alanine Transaminase D. Aspartate transaminase

Alanine Transaminase

What are the names of the 3 uncouplers?

DNP, aspirin, thermogenin (UCP-I)

Arsenic attacks what complex in cellular metabolism?

E2 of pyruvate dehydrogenase complex

T/F: Excess citrate reduces the activity of PDC causing favoribility of nonoxidative glycolysis, pushing increase pyruvate conversion to lactate

True

Increase of citrate activates which of the following enzymes? A. Pyruvate Dehydrogenase B. PFK1 C. Acetyl CoA carboxylase D. All the above

Acetyl CoA Carboxylase - enzyme produces acetyl CoA and Maloney’s CoA pushing lipid synthesis

Transaminases like alanine transaminase or aspartate transaminase require what coenzyme? A. Vitamin B6 derived PLP B. Vitamin B12 cobalamine C. Vitamin B7 biotin D. Vitamin B5 pantothenic acid

Vitamin B6 derived PLP PLP = pyridoxal phosphate

Quiz 1 LOs Flashcards

(108 cards)