CHO - LIPID METABOLISM Flashcards
What glycolytic reaction produces NADH?
A. G6P to F6P
B. F1,6BP to G3P
C. I forgot huehue
D. G3P to BPG
D. G3P to BPG
What liver enzyme hydrolyzes G6P to yield
glucose and Pi?
A. G-6-phosphatase
B. 2,3-BPG
C. Glucokinase
D. Hexokinase
A. G-6-phosphatase
Which of the ff indirectly activates glycogen
phosphorylase in muscle?
A. Calcium
B. Insulin
C. AMP
D. Epinephrine
C. AMP
Liver glycogen contributes to maintenance of
glucose but not muscle glycogen because of
the absence of this enzyme
A. Liver glucokinase
B. Hexokinase
C. Glycogen
D. G-6 phosphatase
D. G-6 phosphatase
In muscle, glycogenolysis is used in
a. muscle relaxation
b. muscle contraction
c. maintaining blood glucose
d. none
b. Muscle contraction
Mr A, 52 y.o, diagnosed with DM type 1 since
2 years ago. He was noted to have lost weight
over the years until a few hours PTC, he
suddenly collapsed during his morning
walk,hence, rushed to the ER. A random blood
sugar was taken revealed 50mg/dl. Which of
the statements regarding glycogenolysis is
correct?
A. Glucose stabilizes the R state of the liver
glycogen phosphorylase A
B. Glucagon stimulates the conversion of
muscle glycogen phosphorylase B to muscle
glycogen phosphorylase A
C. Insulin causes liver cells to convert
glycogen phosphorylase A to phosphorylase
B
D. 5’AMP binds with muscle glycogen
phosphorylase B and inhibits it by allosteric
mechanism
B. Glucagon stimulates the
conversion of muscle
glycogen phosphorylase B to
muscle glycogen
phosphorylase A
Triathlete was training. After vigorous exercise
he felt stiffness and sore. This condition is
associated with the accumulation of this
substance
A. Pyruvate
B. Lactate
C. Acetyl CoA
D. Glycerate
B. Lactate
The following increases blood glucose level.
A. Insulin and glucagon
B. Epinephrine and insulin
C. Estrogen and insulin
D. Epinephrine and glucagon
D. Epinephrine and glucagon
Glycerol is one of the precursors of
gluconeogenesis. It is most likely found in
______.
A. Muscle
B. Erythrocytes
C. Adipose tissue
D. Heart
C. Adipose tissue
Glutathione disulfide (GSSG) is reduced
through which cofactor and enzyme in RBC?
A. NADH; glutathione reductase
B. NADH; glutathione oxidase
C. NADPH; glutathione oxidase
D. NADPH; glutathione reductase
D. NADPH; glutathione
reductase
Transporter of pyruvate across the mitochondrial
membrane
A. Coenzyme A
B. Succinyl CoA
C. Lactate dehydrogenase
D. NAD
A. Coenzyme A
52 yr fasting for 1 week and water diet. which
has higher concentration than overnight fast
A. Glycerol
B. Non esterified fatty acids
C. Ketone bodies
D. Triacylglycerol
C. Ketone bodies
Gi cataract si maam. Sugar that causes it?
C. Sorbitol
Sorbitol is responsible for furctose formation from
glucose!
Enzyme deficiency in essential pentosuria
A. Xylulose reductase
B. Glucoronate reductase
C. Xylitol dehydrogenase
D. Gulonolactone oxidase (not sure)
A. Xylulose reductase
Which of the following is the product of Uronic
Acid Pathway that is a precursor of
proteoglycans:
A. L-Gulonate
B. Glucuronate
C. Xylitol
D. L-ascorbate
B. Glucoronate
Condition in which individuals with cancer, HIV,
AIDS and other chronic diseases are
undernourished:
A. Anorexia
B. Bulimia
C. Cachexia
D. Wasting
C. Cachexia
Essential amino acids except
A. Isoleucine
B. Histidine
C. Lysine
D. Proline
D. Proline
In the glycogen synthase reaction, the precursor to glycogen is
A. UTP-glucose
B. glucose-1-P
C. UDP-glucose
D. glucose-6-P
C. UDP-glucose
Glycogenin catalyzes the transfer of a further seven glucose residues from UDPGlc, in 1 → 4 linkage, to form a glycogen primer that is the substrate for glycogen synthase.
The active form of glycogen phosphorylase is phosphorylated, while the dephosphorylation of which active form occurs?
A. Glycogen hydrolase
B. Glycogen semisynthesis
C. Glycogen dehydrogenase
D. Glycogen synthase
D. Glycogen synthase
Active glycogen synthase a is dephosphorylated and inactive glycogen synthase b is phosphorylated.
Glycogen has:
A. ɑ-1,4 linkage
B. ɑ-1,6 linkages
C. ɑ-1,4 and ß-1,6 linkage
D. ɑ-1,4 and ɑ-1,6 linkage
D. ɑ-1,4 and ɑ-1,6 linkage
a-1->4 linear linkage
a-1->6 - branching linkage
In the pentose phosphate pathway, the major products are:
A. Ribulose and NADH
B. Ribulose and NADPH
C. Ribulose and ATP
D. Ribulose and NAD+
B. Ribulose and NADPH
What is the first reaction of the pentose phosphate pathway?
A. Reduction of ketopentose ribulose 5-phosphate to 6-
phosphogluconate
B. Oxidation of glucose 6-phosphate to 6-phosphoglucono-δ-lactone
C. Oxidation of 6-phosphogluconate to ketopentose ribulose 5-
phosphate
D. Reduction of 6-phospho glucono-δ-lactone to glucose 6-phosphate
B. Oxidation of glucose 6-phosphate to 6-phosphoglucono-δ-lactone
Which of the following statements is correct about oxidative pentose
phosphate pathway?
A. It oxidizes NADPH to NADP+
B. Glucose 6-phosphatase catalyzes the rate limiting reaction of the
pathway
C. The pathway supplies ribose 5-phosphate and NADPH in the
quantities the cell requires
D. It generates NADH
C. The pathway supplies ribose 5-phosphate and NADPH in the quantities the cell requires
Ribose-5-phosphate is essential for purine and pyrimidine synthesis while NADPH is used in TCA and other metabolic cycles
Which one out of the following enzymes acts in the pentose phosphate
pathway?
A. Pyruvate Kinase
B. Glycogen phosphatase
C. 6-phosphogluconate dehydrogenase
D. Aldolase
C. 6-phosphogluconate dehydrogenase
What is the main function of the pentose phosphate pathway?
A. Supply NADH
B. Supply energy
C. Supply NADP+
D. Supply pentoses and NADPH
D. Supply pentoses and NADPH
Which of the following statements is correct about the reductive pentose
phosphate pathway?
A. It is not reversible
B. Transketolase transfers 3 carbon units
C. Pentoses can provide glycolytic intermediates
D. Transaldose transfers 2 carbon units
C. Pentoses can provide glycolytic intermediates
What intermediate in the glycolysis pathway also serves as an
intermediate in Fatty Acid Synthesis?
A. Phosphoenolpyruvate
B. Phosphoglycerate
C. Fructose-b-phosphate
D. Dihydroxyacetone phosphate
D. Dihydroxyacetone phosphate
What Glycogen Storage Disease deals with a deficiency in Lysosomal
glucosidase?
A. Pompe disease
B. Von Gierke disease
C. Hers disease
D. Tarui disease
A. Pompe disease
Which of the following normal conditions increases the risk for ketosis?
1. Pregnancy
2. Diabetes mellitus
3. Lactation
4 Obesity
A. Statement 4 is correct
B. Statements 2 & 4 are correct
C. Statements 1 & 3 are correct
D. Statements 1, 2 & 3 are correct
D. Statements 1, 2 & 3 are correct
Triacylglycerol is packaged as chylomicrons and are transported to which
of the different tissues for processing.
1. Adipose
2. Heart muscle
3. Liver
4. Blood
A. Statements 1 & 3 are correct
B. Statements 2 & 4 are correct
C. Statements 1, 2 & 3 are correct
D. Statement 4 is correct
A. Statements 1 & 3 are correct
This amino acid is considered ketogenic because in prolonged tasting and
starvation, most acetyl-CoA is used for ketogenesis.
A. Tryptophan
B. Isoleucine
C. Phenylalanine
D. Tyrosine
B. Isoleucine
In the presence of ATP and coenzyme A, this enzyme catalyzes the
conversion of fatty acid to acyl-CoA
A. Carnitine palmitoyl transferase
B. Thiolase
C. Thiokinase
D. acyl-CoA dehydrogenase
C. Thiokinase
n general, how many molecules of these reducing equivalents are
generated in each beta-oxidation cycle?
A. 1 NADH and 1 FADH2
B. 8 NADH and 1 FAD
C. 1.5 NADH and 2.5 FADH2
D. 7 NADH and 2 FADH2
A. 1 NADH and 1 FADH2
Which of the following BEST DESCRIBES beta oxidation?
A. Cleavage from acyl-CoA molecules starts at the carboxyl end
with 2 carbons at a time
B. Oxidation via the respiratory chain leads to formation of 80 mol of
ATP
C. The propionyl residue from an even chain fatty acid is glucogenic
D. Very long chain fatty acid oxidation occurs in the mitochondria
A. Cleavage from acyl-CoA molecules starts at the carboxyl end with 2 carbons at a time
Ketogenesis is the process of ketone body formation from the breakdown
of fatty acids. Which of the following LEAST DESCRIBES it?
A. Acetone is the volatile waste product excreted in the lungs
B. In the extrahepatic tissues, acetoacetate is activated to acetoacetyl-
CoA by succinyl-CoA-acetoacetate-CoA transferase
C. Acetyl-CoA is its substrate
D. Occurs when there is a high rate of fatty acid oxidation in the liver
C. Acetyl-CoA is its substrate
Esterification is the 2nd step in the regulation of ketogenesis which occurs
in the ____
A. Adipose tissue
B. Extrahepatic tissues
C. Blood
D. Liver
D. Liver
A reversal reaction in ketogenesis is catalyzed by this enzyme
A. HMG-CoA lyase
B. HMG-CoA synthase
C. Thiolase
D. Acyl-CoA synthetase
C. Thiolase
Diseases associated with impairment of fatty acid oxidation may lead to ___
A. Fatty infiltration of organs
B. Ketoacidosis
C. Hyperketonemia
D. Hyperglycemia
A. Fatty infiltration of organs
Which of the following has the correct match?
A. Elongation of fatty acids-mitochondria (ER)
B. Lipolysis-peroxisomes (adipocytes)
C. Lipogenesis-cytosol
D. Very long chain FA oxidation - endoplasmic reticulum (peroxisomes
C. Lipogenesis-cytosol
Remember, only two pathways occur entirely in the cytosol: lipogenesis and pentose phosphate pathway
Acetyl-CoA carboxylase, an important enzyme in the regulation of
lipogenesis, is inactivated by
A. CO2
B. Malonyl-CoA
C. Citrate
D. Palmitoyl-CoA
D. Palmitoyl-CoA
What is the outcome of the accumulation of acetyl-CoA in the mitochondria
of the liver?
A. It is converted to oxaloacetate
B. It is used an an energy source
C. It forms into ketone bodies
D. It is broken down into fatty acids
C. It forms into ketone bodies
Conversion of acetyl-CoA to malonyl-CoA requires which of the following?
A. NADPH
B. Folic acid
C. Biotin
D. H2O
C. Biotin
Which of the following is an essential fatty acid?
A. Stearic acid
B. Oleic acid
C. Linolenic acid
D. Palmitic acid
C. Linolenic acid
Which of the following converts PGH2 to thromboxane A2?
A. Thromboxane synthase
B. Cyclooxygenase
C. Isomerase
D. Peroxidase
A. Thromboxane synthase
The following drugs inhibit COX1 and COX2, except
A. Ibuprofen
B. Aspirin
C. Corticosteroids
D. Indomethacin
C. Corticosteroids
In the cyclooxygenase pathway, prostaglandin H2 synthase exhibits two
activities:
A. Cyclooxygenase and hydrolase
B. Lipooxygenase and peroxidase
C. Desaturase and elongase
D. Cyclooxygenase and peroxidase
D. Cyclooxygenase and peroxidase
Which membrane fatty acids are precursors for eicosanoids?
A. C18 saturated fatty acids
B. C22 monounsaturated fatty acids
C. C16 unsaturated fatty acids
D. C20 polyunsaturated fatty acids
D. C20 polyunsaturated fatty acids
5-Lipoxygenase, found in leukocytes, catalyzes the conversion of
arachidonate to ____ which is then converted to ____
A. 5-HPETE, Leukotriene C4
B. 5-HPETE, Leukotriene A4
C. 12-HPETE, Leukotriene B4
D. 5-HPETE, Leukotriene B4
B. 5-HPETE, Leukotriene A4
Which of the following hormones is not used in the hydrolysis of
triacylglycerol into the fatty acids in adipose tissue?
A. Insulin
B. Norepinephrine
C. Glucagon
D. Epinephrine
A. Insulin
Which of the following enzymes is not used in the synthesis of
triacylglycerol?
A. Diacylglycerol acyltransferase
B. Phosphatidate phosphohydrolase
C. Glycogen phosphorylase
D. Glycerol-3-phosphate acyltransferase
C. Glycogen phosphorylase
The most active site/sites of triacylglycerol synthesis occurs in the ____
A. Spleen
B. Adipose tissue
C. Liver and intestines
D. Kidney
C. Liver and intestines
Premature infants who develop Respiratory Distress Syndrome (RDS) have
a deficiency of this lipid that act as lung surfactant
A. Phosphatidylinositol
B. Ceramide
C. Phosphatidylethanolamine
D. Phosphatidylcholine
D. Phosphatidylcholine
The lipid most likely found in mitochondrial membranes
A. Cardiolipin
B. Cephalin
C. Ceramide
D. Lecithin
A. Cardiolipin
Insulin enhances the uptake of triacylglycerols in adipose tissues. Which of
the following enzymes is activated facilitating its uptake?
A. Lipoprotein lipase
B. Apo C-II (activates lipoprotein lipase)
C. LCAT (esterification of cholesterol with HDL)
D. Hormone sensitive lipase
A. Lipoprotein lipase
One type of fatty liver is caused by a metabolic block in the production of
plasma lipoproteins, resulting in accumulating triacylglycerols. This
pathologic process is explained by this mechanism.
A. Mobilization of fat from adipose tissue
B. Ability to secrete VLDL
C. Provision of phospholipids found in lipoproteins
D. A block in the synthesis of the lipoprotein from lipid and apolipoprotein
D. A block in the synthesis of the lipoprotein from lipid and apolipoprotein
These hormones act rapidly in promoting lipolysis by stimulating the activity of adenylyl cyclase
A. ACTH
B. Insulin
C. Catecholamines
D. Glucagon
C. Catecholamines
Cholesterol serves as the precursor of the following biosynthesis pathways,
EXCEPT
A. Steroid hormone synthesis
B. Thyroid hormone synthesis
C. Aldosterone synthesis
D. Bile acid synthesis
B. Thyroid hormone synthesis
A child was brought to the hospital with clinical manifestations of mental
retardation, blindness and muscular weakness. The biochemical
examination showed the accumulation of GM2 gangliosides in the tissues,
hence, diagnosed with Tay-Sachs Disease. This lipid storage disease is
caused by a genetic defect of what enzyme?
A. Beta galactosidase
B. Hexosaminidase A
C. Ceramidase
D. Sphingomyelinase
B. Hexosaminidase A
Mr. Alvarez consulted at the ER due to chest pain and dizziness. His BMI
was at 30% and all levels in the lipid panel taken were elevated. Hence, he
was started on Simvastatin and advised dietary modification and regular
exercise. This hypolipidemic drug reduces the cholesterol and
triacylglycerol via this mechanism.
A. Downregulating LDL receptor activity
B. Inhibiting the absorption of cholesterol by the intestine
C. Decreasing the secretion of triacylglycerol and cholesterol-
containing VLDL by the liver
D. Inhibiting HMG-CoA reductase
D. Inhibiting HMG-CoA reductase
The regulatory enzyme in cholesterol biosynthesis
A. HMG-CoA synthase
B. Cholesterol synthase
C. Lanosterol oxidase
D. HMG-CoA reductase
D. HMG-CoA reductase
What is the action of 15-hydroxypostaglandin dehydrogenase in the body?
A. Activates prostaglandins
B. Prolongs half-life of prostaglandins
C. Have no effect on prostaglandins
D. Inactivates prostaglandins
D. Inactivates prostaglandins
The predominant lipid in low-density lipoprotein
A. Triacylglycerol
B. Cholesterol
C. Cholesteryl esters
D. Phospholipid
B. Cholesterol
Fatty acid oxidation is regulated by malonyl-CoA which inhibits ____
A. The entry of fatty acids into the cell
B. Activation of FA to fatty acyl-CoA
C. Dehydration of fatty acyl CoA to enoyl CoA
D. Shuttling of fatty acyl CoA to mitochondria
D. Shuttling of fatty acyl CoA to mitochondria
Which of the following is an integral apolipoprotein present in VLDL, IDL
and LDL?
A. Apo B48
B. ApoE
C. Apo B100
D. Apo CII
C. Apo B100
Which of the following statements about plasma lipoproteins is correct?
A. They have a hydrophobic core of phospholipid and apolipoproteins
B. They have a hydrophilic core of triacylglycerol and cholesterol
esters
C. They have a hydrophobic core of triacylglycerol and
cholesterol esters
D. They have a hydrophobic core of phospholipids and free cholestero
C. They have a hydrophobic core of triacylglycerol and
cholesterol esters
These lipoproteins are produced via the exogenous lipoprotein pathway
A. HDL
B. LDL
C. VLDL
D. chylomicrons
D. chylomicrons
Which of the ff is the major fat in adipose tissues?
A. Sphingolipid
B. Cholesterol
C. TAG
D. Phospholipid
C. TAG
The Addition of this compound leads to formation of PAF (platelet activating factor)
A. CDP-choline
B. Palmitoyl-coa
C. UDP-galactose
D. Phosphatidylcholine
A. CDP-choline
Gangliosides, what is added in glucosylceramide?
A. Glycerol
B. Sialic acid
C. Hyaluronic
D. DAG
B. Sialic acid
When fat is ingested, it appears in the circulation as:
a. VLDL
b. LDL
c. HDL
d. Chylomicron
d. Chylomicron
Cellular Location of enzymes involved in Beta Oxidation lie where?
A. Cytosol
B. ER
C. Mitochondria
C. Mitochondria
Which apolipoprotein is implicated in neurodegenerative disorders in human
A. Apo A
B. Apo B
C. Apo C
D. Apo D
D. Apo D
What C position does oxidation of long chain FA to acetyl CoA
A. Alpha C
B. Beta C
C. Terminal C
D. Carbonyl C
B. Beta C
In the complete degradation of fatty acids, how many ATP is/are used in the mitochondria
A. 0
B. 1
C. 2
D. 3
C. 2
This substance plays a crucial role in exercising muscle tissue as it facilitates the breakdown of fatty acids into energy.
A. Lipoprotein lipase
B. Carnitine
C. Apolipoprotein
D. LCAT
A. Lipoprotein lipase
The enzymes for the biosynthesis of fatty acids are located in?
A. Cytosol
B. Golgi apparatus
C. Mitochondria
D. Endoplasmic reticulum
A. Cytosol
The following enzymes are involved in the synthesis of long chain fatty acids, except:
A. Acetyl-CoA carboxylase most important (rate-limiting)
B. Keto-acyl reductase
C. Acyl-CoA synthetase activation of fatty acids
D. Thioesterase
C. Acyl-CoA synthetase activation of fatty acids
Desaturation and chain elongation reactions in the synthesis of PFA are LEAST likely decreased/diminished in which of the ff cases?
A. Prolonged fasting
B. Fed state
C. Type 1 DM
D. Elevated catecholamine
B. Fed state
45 yr old female cook, aspirin as maintenance.
Which eicosanoids are inhibited?
A. Prostaglandin
B. Leukotriene
C. Thromboxane
D. Lipoxin
A. Prostaglandin
This leukotriene has been implicated in the inflammatory response and immediate hypersensitivity found in asthmatic patients, thus is now a target for therapeutic management
A. Leukotriene B4
B. Leukotriene C4
C. Leukotriene D4
D. Leukotriene E4
A. Leukotriene B4
This hormone stimulates Acetyl-CoA carboxylase
A. Epinephrine
B. Insulin
C. Glucagon
D. Thyroid Hormones
B. Insulin
This toxin has been implicated in the development of Jamaican Vomiting Sickness
A. Coumarin
B. Hypoglycin
C. Amanita
D. Brevetoxin
B. Hypoglycin
This lipid storage disease has symptoms occurring only in male affected individuals
A. Tay-Sachs disease
B. Niemann-Pick disease
C. Fabry disease
D. Gaucher disease
C. Fabry disease
AB has increased lipid panel. She was prescribed one of these drugs which inhibit the absorption of cholesterol in the intestine, thus lowering blood cholesterol levels,
A. Clofibrate
B. Nicotinic Acid
C. Clofibrate
D. Ezetimibe
D. Ezetimibe
Primary source of Acetyl CoA and NADPH used in Fatty Acid Synthesis, except
A. Pyruvate
B. Palmitate
C. Citrate
D. Malate
B. Palmitate
Disorder with long term benefits to the body
A. Abetalipoproteinemia
B. Familial lipoprotein excess
C. Familial hyperalphaproteinemia - increase HDL(good cholesterol)
D. fish eye disease
C. Familial hyperalphaproteinemia
In the presence of an insulin w/c receptor accepts triglyceride into adipose tissue?
VLDL receptor
Which glycolytic intermediate is the precursor for the synthesis of trigly, phosphatidylcholine and phosphatidylethanolamine
A. Pyruvate
B. Glyceraldehyde-3-Phosphate
C. 3-phosphoglycerate
D. Phosphopyruvate
Glycerol-3-Phosphate
Deficiency of hexosaminidase A?
Tay sachs Disease
Ketone body excreted in lungs:
Acetone
Tissues synthesize monounsaturated fatty acids from saturated fatty acids usually introduce 1st double bond to what position?
A. Delta 4
B. Delta 5
C. Delta 6
D. Delta 9
D. Delta 9
What enzyme is produced in the body and is considered not essential in the diet?
A. Proline
B. Alanine
C. Arginine
D. Histidine
B. Alanine
