Exam 3 Practice Exams

Question 1

Please select the false statement:

a. Cholesterol is used as a membrane lipid
b. Cholesterol is used precursor to steroid hormones
c. Cholesterol is used as a precursor to bile salts
d. Cholesterol is used as a precursor to phosphatidylinositol

Answer 1

d. Cholesterol is used as a precursor to phosphatidylinositol

Question 2

Please select the equivalent of: 16:1 cis-∆ 9

a. CH3CH2 CH2 CH2 CH2 CH=CH CH2 CH2 CH2 CH2 CH2 CH2 CH2 CH2 CH2 CH2 COO-
b. CH3CH2 CH2 CH2 CH2 CH2 CH2 CH2 CH2 CH= CH CH2 CH2 CH2 CH2 COO-
c. CH3CH2 CH2 CH2 CH2 CH2 CH2 CH2 CH=CH CH2 CH2 CH2 CH2 COO-
d. CH3CH2 CH2 CH2 CH2 CH2 CH=CH CH2 CH2 CH2 CH2 CH2 CH2 CH2 COO-
e. None of the above are correct

Answer 2

d. CH3CH2 CH2 CH2 CH2 CH2 CH=CH CH2 CH2 CH2 CH2 CH2 CH2 CH2 COO-

Question 3

Which fatty acid is an omega 6 fatty acid?

a. CH3CH2 CH2 CH2 CH2 CH=CH CH2 CH2 CH2 CH2 CH2 CH2 CH2 CH2 CH2 CH2 COO-
b. CH3CH2 CH2 CH2 CH2 CH2 CH2 CH2 CH2 CH= CH CH2 CH2 CH2 CH2 COO-
c. CH3CH2 CH2 CH2 CH2 CH2 CH2 CH2 CH=CH CH2 CH2 CH2 CH2 COO-
d. CH3CH2 CH2 CH2 CH2 CH2 CH=CH CH2 CH2 CH2 CH2 CH2 CH2 CH2 COO-
e. None of the above are correct

Answer 3

a. CH3CH2 CH2 CH2 CH2 CH=CH CH2 CH2 CH2 CH2 CH2 CH2 CH2 CH2 CH2 CH2 COO-

Question 4

Please select the true statement:

a. Bile salts are made in the small intestine
b. Bile salts are both polar and non polar
c. Bile salts reduce the ability of lipids to be suspended in aqueous solution.
d. None of the above is true.

Answer 4

b. Bile salts are both polar and non polar

Question 5

Fats are another term for all lipids, including cholesterol, phospholipids and triacylglycerol.

a. True
b. False

Answer 5

b. False

Question 6

Please select the true statement:

a. Formation of fatty acyl-Coenzyme A is the first step in cholesterol synthesis.
b. Formation of fatty acyl-Coenzyme A allows β-oxidation of fatty acid chains longer than 8C.
c. Fatty acyl CoA synthesis is required for phosphatidate synthesis
d. Only a and b are true
e. Only b and c are true

Answer 6

e. Only b and c are true

Question 7

Phosphatidate is a precursor in the synthesis of all except:

a. Ceramide
b. Phospholipids
c. Triacylglycerols
d. Actually, all the above have phosphatidate as a precursor.

Answer 7

a. Ceramide

Question 8

In a cell that needed only NADPH in large amounts, what numbered pathways would be used?

1. Oxidative pentose phosphate pathway, forward
2. Non-oxidative pentose phosphate pathway, forward
3. Non-oxidative pentose phosphate pathway, backward
4. Glycolysis
5. Gluconeogenesis
6. TCA cycle
7. Electron transport chain

a. 1,2, and 5 only
b. 3 only
c. 1 and 2 only
d. 1,2, and 4 only
e. 1,2, 4, 6 and 7 only
f. None of the above

Answer 8

a. 1,2, and 5 only

Question 9

In a cell that needed only nucleotides, not NADPH, in large amounts, what numbered pathways would be used?

1. Oxidative pentose phosphate pathway, forward
2. Non-oxidative pentose phosphate pathway, forward
3. Non-oxidative pentose phosphate pathway, backward
4. Glycolysis
5. Gluconeogenesis
6. TCA cycle
7. Electron transport chain

a. 1,2, and 5 only
b. 3 only
c. 1 and 2 only
d. 1,2, and 4 only
e. 1,2, 4, 6 and 7 only
f. None of the above

Answer 9

b. 3 only

Question 10

Please select the true statement:

a. The reactions of fatty acid synthesis occur in the mitochondria
b. Acetyl CoA carboxylase is the enzyme that regulates the rate of fatty acid beta-oxidation.
c. The formation of acetyl Co A from malonyl-CoA by decarboxylation is the committed step of fatty acid synthesis.
d. Citrate is a potent activator of fatty acid synthesis.

Answer 10

d. Citrate is a potent activator of fatty acid synthesis.

Question 11

Inhibition of the electron transport chain by antimycin would have what effect on Complexes I and IV:

a. Both Complex I and IV would be oxidized.
b. Complex I would be reduced, Complex IV would be oxidized.
c. Both Complex I and IV would be reduced.
d. Complex I would be oxidized, Complex IV would be reduced.
e. None at all, their function would not be affected and ATP would still be produced.

Answer 11

b. Complex I would be reduced, Complex IV would be oxidized.

Question 12

Which would increase glycogen production in the liver?

a. Insulin levels are high.
b. Glycogen phosphorylase is activated by phosphorylation
c. The global effectors, epinephrine and glucagon have bound their receptors to activate second messenger systems
d. None of the above
e. a and b only

Answer 12

a. Insulin levels are high

Question 13

During fatty acid synthesis, the progression of reactions is (in this order) :

a. Oxidation, reduction, oxidation, thiolysis
b. Condensation, reduction, dehydration, reduction
c. Oxidation, hydration, oxidation, thiolysis
d. None of the above is correct.

Answer 13

b. Condensation, reduction, dehydration, reduction

Question 14

During fatty acid synthesis, the condensation of an acetyl group is driven forward in part by CO2 release from the three-carbon malonyl group attached to the Acyl Carrier protein, in this way, the human body primarily generates even-numbered fatty acids, added in two carbon units.

a. True
b. False

Answer 14

a. True

Question 15

Please select the true statement:

a. Local control of glycogen phosphorylase by free glucose in the liver increases the tendency of this enzyme to be in the relaxed state.
b. Glycogen phosphorylase breaks alpha 1,4-glycosidic bonds to release glucose 6-phosphate.
c. Glycogen phosphorylase breaks down alpha 1,6-glycosidic bonds to release free glucose.
d. None of the above is true.

Answer 15

d. None of the above is true.

Question 16

Please select the true statement:

a. Sphingolipids are a class of membrane lipids found in all tissues, but with highest concentrations the central nervous system.
b. Desaturation of fatty acids occurs in the mitochondrion.
c. Respiratory distress syndrome in premature infants can be caused by insufficient formation of dipalmitoyl phosphatidylcholine.
d. Only a and c are true.
e. None of the above is true

Answer 16

d. Only a and c are true.

Question 17

Please select the true statement:

a. Favism results from a mutation in glycogen synthase, and although it is usually subclinical, its symptoms are seen when the patient eats fava beans in sufficient quantities.
b. Mutations in glucose 6-phosphate dehydrogenase can result in hemolytic anemia.
c. NADPH is necessary in red blood cells to oxidize glutathione.
d. Only a and b are correct
e. Only a and c are correct
f. None of the above is correct.

Answer 17

b. Mutations in glucose 6-phosphate dehydrogenase can result in hemolytic anemia.

Question 18

The main product of fatty acid synthase is the 16-carbon fatty acid, palmitate.

a. True
b. False

Answer 18

a. True

Question 19

The human body cannot break down odd-numbered fatty acids.

a. True
b. False

Answer 19

b. False

Question 20

When the malate aspartate shuttle is used, reducing equivalents enter the mitochondrial matrix as:

a. Oxaloacetate
b. Malate
c. Alpha-ketoglutarate
d. Aspartate
e. FADH2

Answer 20

b. Malate

Question 21

Methylmalonyl CoA mutase catalyzes an intramolecular rearrangement that requires vitamin B12, (cobalamin) and produces succinyl CoA.

a. True
b. False

Answer 21

a. True

Question 22

Please select the true statement:

a. Malonyl Co A is formed as an activated intermediate for cholesterol synthesis.
b. Geranyl pyrophosphate is a 5-carbon intermediate of cholesterol synthesis.
c. Farnesyl pyrophosphate is an intermediate derived from 2 activated isoprene units and is a 10C
d. Synthesis of one molecule of 3-isopentyl pyrophosphate requires HMG CoA (3-hydroxy,3-methylglutaryl CoA), and 3 molecules of ATP.

Answer 22

d. Synthesis of one molecule of 3-isopentyl pyrophosphate requires HMG CoA (3-hydroxy,3-methylglutaryl CoA), and 3 molecules of ATP.

Question 23

Please select the true statement:

a. VLDLs are apolipoproteins formed in the liver and they contain only triacylglycerol.
b. The primary lipid in chylomicrons is cholesterol.
c. VLDLs contain triacylglycerol of dietary origin.
d. Chylomicron remnants carry dietary lipids to the liver.

Answer 23

d. Chylomicron remnants carry dietary lipids to the liver.

Question 24

Please select the true statement:

a. Apoprotein B100 is found in in circulating VLDLs.
b. Apoprotein B48 is found in in circulating LDLs.
c. Apoprotein CII activates lipoprotein lipase.
d. All of the above are true.
e. Only a and c are true.
f. Only b and c are true.

Answer 24

e. Only a and c are true.

Question 25

HDLs can transport cholesterol from foam cells to the liver.

a. True
b. False

Answer 25

a. True

Question 26

Hydration of the double bond in fumarate yields which of the following intermediates?

a. Oxaloacetate
b. Malate
c. Succinate
d. Alpha-ketoglutarate

Answer 26

b. Malate

Question 27

Is the reaction that generates ATP or GTP during the TCA cycle reversible?

a. yes
b. no

Answer 27

a. yes

Question 28

High citrate levels are primarily generated when the body is fasting.

a. True
b. False

Answer 28

b. False

Question 29

Acetyl groups are intermediates in the synthesis of:

a. Fatty acids
b. Cholesterol
c. Glucose
d. All the above.
e. Only a and b

Answer 29

e. Only a and b

Question 30

If heme synthesis was high, and the only input to the TCA cycle was acetyl-CoA, the cycle eventually be forced to stop

a. True
b. False.

Answer 30

a. True

Question 31

Please list, in forward direction of the cycle, the enzyme in the TCA cycle that comes immediately after Isocitrate dehydrogenase

Answer 31

Alpha-ketoglutarate dehydrogenase

Question 32

What are the products of isocitrate dehydrogenase?

Answer 32

Alpha-ketoglutarate, NADH, H+, and CO2

Question 33

Please list, in forward direction of the cycle, the enzyme in the TCA cycle that comes immediately after Succinate dehydrogenase.

Answer 33

Fumarase

Question 34

What are the products of succinate dehydrogenase?

Answer 34

Fumarate, FADH2

Question 35

Please list, in forward direction of the cycle, the enzyme in the TCA cycle that comes immediately after Citrate synthase

Answer 35

Aconitase

Question 36

Which enzyme in the TCA cycle synthesizes (GTP or ATP?)

Answer 36

Succinyl CoA synthetase

Question 37

In the Citric acid cycle one molecule of nucleotide monophosphate, either ATP or GTP, is made in one “turn of the cycle”. What else is true of this cycle?

a. 2 molecules of NADH and 1 molecule of FADH2 are produced for each turn of this cycle.
b. The enzyme α-ketoglutarate dehydrogenase catalyzes production of succinate.
c. 2 molecules of CO2 are produced for each turn of this cycle.
d. The enzyme isocitrate dehydrogenase catalyzes production of isocitrate.

Answer 37

c. 2 molecules of CO2 are produced for each turn of this cycle.

Question 38

The main objects of the TCA cycle are making metabolites that are building blocks for synthetic reactions, and making reducing equivalents that can be used during the process of oxidative phosphorylation to produce ATP.

a. True
b. False

Answer 38

a. True

Question 39

For every mole of glucose that proceeds through glycolysis to the TCA cycle, how many moles of ATP are made?

a. Four
b. Two
c. 30 if the malate – aspartate shuttle is used.
d. 32 if the malate – aspartate shuttle is used.
e. 36 if the malate – aspartate shuttle is used.
f. 38 if the malate – aspartate shuttle is used.

Answer 39

d. 32 if the malate – aspartate shuttle is used.

Question 40

Please select the true statement regarding electron transfer:

a. FADH2 produced by the glycerol 3-phosphate shuttle directly reduces complex II.
b. NADH and FADH2 each have a P/O ratio of 2.5
c. Electrons from Complex I directly reduce Complex II
d. Electrons from Cytochrome c(reduced) directly reduce Complex IV

Answer 40

d. Electrons from Cytochrome c(reduced) directly reduce Complex IV

Question 41

The TCA cycle takes place in both the cytoplasm and in the mitochondrion.

a. True
b. False

Answer 41

b. False

Question 42

Please choose from the options below to make this a true statement: The last three reactions of the TCA cycle are…

a. similar to the progression of reactions in beta-oxidation.
b. catalyzed by succinyl CoA synthetase, succinate dehydrogenase, and fumarase,
c. directly responsible for production of 2 moles of NADH for each round of the cycle. .
d. Only a and b truthfully complete the sentence.
e. Only b and c truthfully complete the sentence.

Answer 42

a. similar to the progression of reactions in beta-oxidation.

Question 43

What effect do glucagon and epinephrine have on fatty acid synthesis?

a. These global signals decrease the rate of fatty acid synthesis.
b. These local signals decrease the rate of fatty acid synthesis.
c. These global signals increase the rate of fatty acid synthesis.
d. These local signals increase the rate of fatty acid synthesis.

Answer 43

a. These global signals decrease the rate of fatty acid synthesis.

Question 44

HMG Co A Reductase is an integral membrane protein that catalyzes the first committed step in cholesterol synthesis.

a. True
b. False

Answer 44

b. False

Question 45

Please chose the false statement:

a. The carrier of acyl groups during fatty acid synthesis is the acyl carrier protein and a cysteine within fatty acid synthase itself.
b. Fatty acid synthase catalyzes both the formation of fatty acids, and their desaturation.
c. Fatty acid synthesis is inhibited by it product, palmitate
d. The maximum length of a fatty acid made by fatty acid synthase alone is 16 carbons.

Answer 45

b. Fatty acid synthase catalyzes both the formation of fatty acids, and their desaturation.

Question 46

Please chose the false statement regarding the catabolism of odd-numbered fatty acids:

a. Propionyl CoA is converted to an intermediate of the TCA cycle, succinyl CoA.
b. This catabolism requires vitamin B12 derivative, tetrahydrofolate.
c. During this catabolism, propionyl CoA is converted to methylmalonyl CoA in an ATP-dependent carboxylation, that requires biotin.
d. Cobalt is a cofactor required for free radical generation during this catabolism.

Answer 46

b. This catabolism requires vitamin B12 derivative, tetrahydrofolate.

Question 47

Please chose the true statement:

a. H2O is added in trans across the double bond of fumarate to yield L-Malate.
b. Catabolism of fatty acids occurs in both the mitochondrial matrix and peroxisomes in mammals.
c. Acetyl CoA cannot pass through inner mitochondrial membrane.
d. All of the above are true.
e. Only a and b are true.

Answer 47

d. All of the above are true.

Question 48

Please chose the true progression of reactions in fatty acid synthesis, beginning to end:

a. Oxidation, Hydration, Oxidation, Thiolysis
b. Thiolysis, Oxidation, Hydration, Oxidation
c. Condensation, Reduction, Dehydration, Reduction
d. Condensation Dehydration, Reduction, Dehydration

Answer 48

c. Condensation, Reduction, Dehydration, Reduction

Question 49

Ketone bodies are derivatives of acetyl CoA, used for energy production in heart and are also used in the brain when carbohydrates stores are low or glucose metabolism is impaired.

a. True
b. False

Answer 49

a. True

Question 50

What effect does phosphorylation have on the following? Please choose the correct effect.

a. Glycogen phosphorylase activity decreases when this enzyme is phosphorylated.
b. Acetyl CoA carboxylase activity increases when this enzyme is phosphorylated.
c. Glycogen synthase activity increases when this enzyme is phosphorylated.
d. Glycogen phosphorylase kinase activity increases when this enzyme is phosphorylated.
e. Only b, c, and d are true.
f. Only a and d are true.

Answer 50

d. Glycogen phosphorylase kinase activity increases when this enzyme is phosphorylated.

Question 51

Which of these pathways occurs in the mitochondrion?

a. Cholesterol synthesis
b. Glycogen synthesis
c. Fatty acid synthesis
d. None of these occur in the mitochondrion.
e. Each of these pathways occurs in the mitochondrion.

Answer 51

d. None of these occur in the mitochondrion.

Question 52

What is true of the fatty acid shown here:
CH3-CH2-CH=CH-CH2-CH2- CH2-CH2- CH2-CH2-CH2-COOH
a. It is noted as 12:1∆9
b. It is an omega 9 fatty acid
c. It is noted as 12:1∆3
d. It is noted as 12:9∆3
e. Only a and b are true.

Answer 52

a. It is noted as 12:1∆9

Question 53

Please choose the true statement:

a. Glycogen synthesis requires glucose 1-P as an activated synthetic activated precursor.
b. Glycogenin is a necessary primer molecule for initiating synthesis of a new glycogen macromolecule.
c. Straight chains of glycogen have an α-1,6 linkage
d. Glycogen branch points have an α-1,4 linkage.
e. All the above are true.
f. Only a and d are true.

Answer 53

b. Glycogenin is a necessary primer molecule for initiating synthesis of a new glycogen macromolecule.

Question 54

Please select the true statement:

a. Tay-Sachs is a fatal neurodegenerative condition caused by a failure in dipalmitoyl phosphatidylcholine formation.
b. The enzyme, β-N-acetylhexosaminidase, produces a vital component of the surfactant that coats the lung surface, and is deficient in infants with respiratory distress syndrome.
c. Neither a nor b is true.
d. Both a and b are true.

Answer 54

c. Neither a nor b is true.

Question 55

Please select the true statement:

a. The most common fatty acids in mammals are 20 carbons in length.
b. The fatty acids in archea membrane lipids are generally branched.
c. The double bonds in mammalian fatty acids are in the trans configuration.
d. Polyunsaturated double bonds in mammalian fatty acids are generally separated by 4 C.

Answer 55

b. The fatty acids in archea membrane lipids are generally branched.

Question 56

α-ketoglutarate dehydrogenase is inhibited by high cellular concentrations of succinyl CoA.

a. True
b. False

Answer 56

a. True

Question 57

Please select the true statement:

a. Phosphatidate is an activated intermediate in triacylglycerol synthesis and in the synthesis of glycerophospholipids.
b. Glycerol phosphate acyltransferase catalyzes synthesis of phosphatidate from pyruvate.
c. Phospholipids are made up of one or more fatty acids linked to a glycerol or sphingosine backbone, and also contain a phosphate group to which is linked an alcohol head group.
d. All the above are true.
e. Only a and c are true.

Answer 57

e. Only a and c are true.

Question 58

Please select the true statement regarding bile salts:

a. Bile salts are derivatives of cholesterol and are less polar in nature than cholesterol.
b. Bile salts are synthesized in the gall bladder
c. Bile salts are released into the stomach
d. The main role of bile salts is to emulsify triacylglycerols.

Answer 58

d. The main role of bile salts is to emulsify triacylglycerols.

Question 59

Please select the true statement:

a. Chylomicrons are the least dense of any lipoprotein particle.
b. Chylomicrons contain mostly triacylglycerols of endogenous origin.
c. VLDLs contain mostly cholesterol and cholesterol esters.
d. HDLs are chiefly responsible for delivering cholesterol to the peripheral tissues.

Answer 59

a. Chylomicrons are the least dense of any lipoprotein particle.

Question 60

Please select the true statement:

a. Apolipoprotein B100 is the primary apolipoprotein found on circulating chylomicrons.
b. The chief function of apolipoprotein CII is to bind LDL receptors and facilitate endocytosis of the receptor-bound LDL particle.
c. VLDLs are formed from LDLs.
d. LDLs can slip between endothelial cells lining blood vessels and cause inflammation.

Answer 60

d. LDLs can slip between endothelial cells lining blood vessels and cause inflammation.

Question 61

Which of the following is false regarding regulation of fatty acid synthesis:

a. Citrate is an allosteric activator of acetyl-CoA carboxylase as it enhances formation of the active acetyl-CoA carboxylase fiber.
b. Glucagon and epinephrine have an inhibitory effect on fatty acid synthesis.
c. Palmitate promotes citrate export from the mitochondrial matrix
d. Citrate activates acetyl-CoA carboxylase regardless of the phosphorylation state of this enzyme.

Answer 61

c. Palmitate promotes citrate export from the mitochondrial matrix

Question 62

Please select the true statement:

a. Two moles of NADPH are consumed in the oxidative pentose phosphate pathway.
b. The rate-limiting step of the oxidative pentose phosphate pathway is catalyzed by glucose 6-phosphate dehydrogenase.
c. If the cell needs ribose 5-P for nucleotide synthesis, but not NADPH, only the oxidative portion of the pentose phosphate pathway will be used.
d. If the cell needs large quantities of NADPH but not ATP or nucleotides, only the oxidative portion of the pentose phosphate pathway will be used.

Answer 62

b. The rate-limiting step of the oxidative pentose phosphate pathway is catalyzed by glucose 6-phosphate dehydrogenase.

Question 63

Oxygen is the final electron acceptor in the electron transport chain.

a. True
b. False

Answer 63

a. True

Question 64

the intermediate formed by Acetyl CoA and oxaloacetate

Answer 64

citrate

Question 65

The intermediate after citrate in the TCA cycle

Answer 65

isocitrate

Question 66

The intermediate after isocitrate in the TCA cycle

Answer 66

Alpha-ketoglutarate, CO2, NADH and H+

Question 67

The intermediate after alpha-ketoglutarate in the TCA cycle

Answer 67

Succinyl CoA, CO2, NADH, and H+

Question 68

The intermediate after succinyl CoA in the TCA cycle

Answer 68

Succinate, ATP (or GTP), and CoA

Question 69

Which component of the oxidative phosphorylation pathway is poisoned by antimycin?

Answer 69

Complex III

Question 70

If this complex were poisoned by antimycin, would Cytochrome c be found in the oxidized or reduced state?

Answer 70

Oxidized

Question 71

Which steroid hormone acts on the kidneys to regulate blood pressure and blood volume?

Answer 71

Mineralcorticosteroid

Question 72

What is the mechanism by which uncouplers of the oxidative phosphorylation pathway function?

Answer 72

Uncouplers provide another way for H+ to move from the mitochondrial intermediate membrane space to the mitochondrial matrix and bypass ATP synthase. This reduces the chemiosmotic gradient without production of ATP. Energy from the chemiosmotic force is transformed to hear in this process.

Question 73

Palmitate promotes citrate export from the mitochondrial matrix.

a. True
b. False

Answer 73

b. False

Question 74

Please choose the true statement:

a. Linolenic acid is an essential fatty acid
b. Aldosterone is a precursor for all other steroid hormones
c. Glucocorticosteroid decreases blood glucose levels, and has pro-inflammatory effects
d. Cortisol increases blood volume, and blood pressure.

Answer 74

a. Linolenic acid is an essential fatty acid

Question 75

Please select the True statement:

a. The TCA cycle is a pathway that takes place in the cytosol.
b. The TCA cycle produces 2 molecules of FADH2 and 1 molecule of NADH for every turn of the cycle.
c. The TCA cycle is inhibited by low ATP concentration.
d. Intermediates in the TCA cycle are replenished through anapleurotic reactions

Answer 75

d. Intermediates in the TCA cycle are replenished through anapleurotic reactions

Question 76

When the TCA cycle is proceeding in the forward direction, which trio of intermediates is listed in the correct order, with no gaps?

a. Alpha-ketoglutarate, succinate, succinyl CoA
b. Isocitrate, Succinyl CoA, Fumarate
c. Succinyl CoA, Succinate, Fumarate
d. Succinyl CoA, Fumarate, Malate

Answer 76

c. Succinyl CoA, Succinate, Fumarate

Question 77

The α-ketoglutarate dehydrogenase complex requires the cofactor Thiamine Pyrophosphate.

a. True
b. False

Answer 77

a. True

Question 78

Which statement correctly describes the movement of reducing equivalents across the inner mitochondrial membrane?

a. The glycerol phosphate shuttle reduces dihydroxyacetone phosphate (DHAP) to form glycerol 3-phosphate and NAD+.
b. The malate-aspartate shuttle reduces oxaloacetate to form malate and FADH2.
c. The glycerol phosphate shuttle oxidizes DHAP to form glycerol 3-phosphate and NAD+.
d. The malate-aspartate shuttle moves oxaloacetate out of the mitochondrial matrix.
e. The malate-aspartate shuttle oxidizes oxaloacetate to form malate and FADH2.

Answer 78

a. The glycerol phosphate shuttle reduces dihydroxyacetone phosphate (DHAP) to form glycerol 3-phosphate and NAD+.

Question 79

Which poison is correctly paired?

a. Antimycin – Complex IV
b. CO – Complex I
c. Amytal – Complex II
d. Azide –Complex IV
e. Oligomycin –Complex III

Answer 79

d. Azide –Complex IV

Question 80

Please choose the false statement:

a. Ubiquinone is lipid-soluble electron carrier.
b. Complex II is oxidized by FAD
c. Cytochrome C reduces Complex IV
d. Ubiquinone is reduced by Complex II

Answer 80

b. Complex II is oxidized by FAD

Question 81

The ultimate electron acceptor in the electron transport chain is:

a. FAD
b. ½ O2 c. NAD+
d. H2O
e. ATP-synthase

Answer 81

b. ½ O2

Question 82

Please choose the true statement:

a. Chylomicrons are assembled in the liver, and contain apoB-48.
b. VLDL are assembled by the liver, and contain apoB-100.
c. The lipid content of LDL is primarily triacylglycerol.
d. The primary function of apo C II is to promote endocytosis of LDL particles by the liver

Answer 82

b. VLDL are assembled by the liver, and contain apoB-100

Question 83

Please choose the true statement:

a. Mammals can use acetyl CoA for net conversion to glucose.
b. Thermogenin is a poison of ubiquinone.
c. Oxaloacetate is an intermediate in the synthesis of aspartate, other amino acids, and nucleotides.
d. Glucagon is a hormone released from the liver in response to low serum glucose levels

Answer 83

c. Oxaloacetate is an intermediate in the synthesis of aspartate, other amino acids, and nucleotides.

Question 84

During fatty acid synthesis, citrate acts an allosteric activator of acetyl CoA carboxylase, as it enhances the formation of the active acetyl CoA carboxylase polymer.

a. True
b. False

Answer 84

a. True

Question 85

Please choose the true statement:

a. Cholesterol is a sterol that is made even more hydrophobic during production of bile salts.
b. Ceramide is a sphingolipid intermediate used to make cerebrosides and sphingomyelin.
c. Phospholipids like phosphatidyl ethanolamine have a phosphate sugar head group.
d. Synthesis of phospholipids requires UTP and is driven forward by PPi hydrolysis.

Answer 85

b. Ceramide is a sphingolipid intermediate used to make cerebrosides and sphingomyelin.

Question 86

The committed step in cholesterol synthesis…

a. …occurs in the mitochondrion.
b. …requires ATP.
c. …requires NADPH
d. …results in production of HMG CoA (3-hydroxy-3-methylglutaryl CoA)
e. a and d only.
f. c and d only

Answer 86

c. …requires NADPH

Question 87

Please choose the listing of 3 intermediates in cholesterol synthesis ordered correctly, with no gaps.

a. geranyl pyrophosphate, farnesyl pyrophosphate
b. HMG CoA, isopentyl pyrophosphate, isoprene
c. Geranyl pyrophosphate, squalene, isoprene
d. Isoprene, geranyl pyrophosphate, squalene

Answer 87

a. geranyl pyrophosphate, farnesyl pyrophosphate

Question 88

Please choose the true statement:

a. Glycogen phosphorylase a is less active than glycogen phosphorylase b
b. Glycogen phosphorylase a is phosphorylated, while glycogen phosphorylase b is not phosphorylated.
c. Glucagon promotes glycogen synthesis.
d. Glycogen phosphorylase is activated as part of a second messenger cascade activated by insulin.
e. Both c and d are correct.

Answer 88

b. Glycogen phosphorylase a is phosphorylated, while glycogen phosphorylase b is not phosphorylated.

Question 89

Please choose the true statement:

a. When only ribose is needed, only the oxidative pentose phosphate pathway will be active.
b. When only high amounts of NADPH are needed, only the oxidative pentose phosphate pathway will be active.
c. Glutathione oxidation requires NADPH.
d. Red blood cells are especially sensitive to glucose 6-phosphate dehydrogenase deficiency.
e. Only c and d are true
f. Only a and d are true.

Answer 89

d. Red blood cells are especially sensitive to glucose 6-phosphate dehydrogenase deficiency.

Question 90

Glycogen phosphorylase releases free glucose directly from straight chains of glycogen.

a. True
b. False

Answer 90

b. False

Question 91

Glycogen is synthesized when:

a. insulin levels are low
b. glycogen phosphorylase and glycogen synthase are dephosphorylated.
c. stimulated in response to the global effectors, epinephrine and glucagon
d. Only a and b are true.

Answer 91

b. glycogen phosphorylase and glycogen synthase are dephosphorylated.

Question 92

What is the product of acetyl CoA carboxylase?

a. Acetyl Co A
b. Malonyl Co A
c. Citrate
d. Oxaloacetate
e. Pyruvate

Answer 92

b. Malonyl Co A

Question 93

Identify the component of oxidative phosphorylation that is poisoned by the following:
Amytal

Answer 93

Complex I

Question 94

Identify the component of oxidative phosphorylation that is poisoned by the following:
CO

Answer 94

Complex IV

Question 95

What pathology is associated with the following:

Glucose 6-phosphate dehydrogenase deficiency

Answer 95

Favism, Hemolytic anemia

Question 96

What pathology is associated with the following: β-N-acetylhexosaminidase

Answer 96

Tay-Sachs Disease

Question 97

If the electron transport chain were poisoned with antimycin, what
would the oxidation state of the following carriers be, oxidized or reduced?
Ubiquinone

Answer 97

Reduced

Question 98

If the electron transport chain were poisoned with antimycin, what
would the oxidation state of the following carriers be, oxidized or reduced?
Cytochrome C

Answer 98

Oxidized

Question 99

Besides a glycogen chain with one less glucosyl residue, please name the immediate product of glycogen phosphorylase.

Answer 99

Glucose 1-P

Question 100

Please choose the True statement:

a. The TCA cycle produces 3 molecules of NADH for every acetyl CoA group that enters the cycle.
b. The TCA cycle takes place in the cytosol.
c. Three-carbon Acetyl Co A condenses with 3C citrate to produce the 6C intermediate, isocitrate.
d. The intermediate, fumarate is hydrated through a reaction catalyzed by fumarase to make the intermediate malate.
e. All the above are true.
f. Only a and d are true.

Answer 100

f. Only a and d are true.

Question 101

Please choose the True statement:

a. Two molecules of CO2 are produced by TCA cycle for every acetyl CoA group that enters the cycle.
b. The overall rate of catalysis in the TCA cycle is up‐regulated by high levels of ATP.
c. The rate of the TCA cycle is influenced primarily through regulation of the enzyme malate dehydrogenase.
d. Only a and b are true

Answer 101

a. Two molecules of CO2 are produced by TCA cycle for every acetyl CoA group that enters the cycle.

Question 102

The alpha-ketoglutarate dehydrogenase enzyme complex requires several cofactors, which include: Coenzyme A, NAD+, and FAD.

a. True
b. False

Answer 102

a. True

Question 103

Please choose the True statement regarding the use of TCA intermediates in other pathways:

a. Oxaloacetate is used to produce nucleotides and some amino acids.
b. Succinyl CoA is used in heme synthesis.
c. Alpha-ketoglutarate is used to produce amino acids and nucleotides.
d. All the above are true
e. Only a and c are true.

Answer 103

d. All the above are true

Question 104

Mammals use acetyl CoA to make which of the following:

a. Fatty acids, steroids, glucose and citrate
b. Fatty acids, glucose, citrate and ketone bodies
c. Fatty acids and citrate only
d. Fatty acids, citrate, ketone bodies and steroids

Answer 104

d. Fatty acids, citrate, ketone bodies and steroids

Question 105

Ubiquinol is formed when ubiquinone accepts electrons from Complex III

a. True
b. False

Answer 105

b. False

Question 106

If mitochondria were poisoned by addition of cyanide, which of the following would be true:

a. Complex III would be poisoned directly.
b. Complex II would be poisoned directly.
c. Complex I would be poisoned directly.
d. Complex IV would be poisoned directly.

Answer 106

d. Complex IV would be poisoned directly.

Question 107

Please choose the True statement:

a. Fatty acids are synthesized in the mitochondrial matrix.
b. Citrate is an inhibitor of fatty acid synthesis
c. Production of acetyl CoA is the first committed step in fatty acid synthesis.
d. There are no true answers here.

Answer 107

d. There are no true answers here.

Question 108

In order, reactions of fatty acid synthesis are: condensation, oxidation, hydration, oxidation.

a. True
b. False

Answer 108

b. False

Question 109

Phosphorylase a, which is used in glycogen metabolism, is less active than phosphorylase b.

a. True
b. False

Answer 109

b. False

Question 110

Please choose the false statement:

a. De novo glycogen synthesis requires the primer, glycogenin.
b. Glucose-6 phosphate is released from glycogen branchpoints by the debranching enzyme.
c. Glucagon binding to its receptor results in downstream activation of adenylyl cyclase.
d. Glucagon is a hormone produced in the pancreas.

Answer 110

b. Glucose-6 phosphate is released from glycogen branchpoints by the debranching enzyme.

Question 111

Please choose the true statement:

a. Sphingolipids, glycolipids, phospholipids and cholesterol are all used as membrane lipids.
b. Cholesterol is used as a synthetic precursor of NAD+
c. Cholesterol esters have a Coenzyme A attached to the hydroxyl group
d. Biosynthesis of cholesterol occurs in the mitochondrion.

Answer 111

a. Sphingolipids, glycolipids, phospholipids and cholesterol are all used as membrane lipids.

Question 112

Please choose the false statement:

a. Apolipoprotein B-48 is only made in the small intestine.
b. In individuals homozygous for familial hypercholesterolemia, too much LDL remains in the blood.
c. LDL receptor synthesis is regulated by cholesterol levels, such that high serum cholesterol results in an increase in LDL receptor synthesis.
d. The lipids in LDL particles are mainly comprised of cholesterol and cholesterol esters

Answer 112

c. LDL receptor synthesis is regulated by cholesterol levels, such that high serum cholesterol results in an increase in LDL receptor synthesis.

Question 113

Please choose the true statement:

a. VLDL are formed in the liver and the lipids contained in them are mostly triacylglycerols of dietary origin.
b. HMG-CoA reductase catalyzes the rate-limiting step in cholesterol synthesis.
c. Glucocorticosteroids are derivatives of arachadonic acid.
d. Bile salts are made primarily from fatty acids and are used to emulsify dietary lipids

Answer 113

b. HMG-CoA reductase catalyzes the rate-limiting step in cholesterol synthesis.

Question 114

Please choose the true statement:

a. Isopentenyl pyrophosphate is made when AMP levels in the cell are high.
b. In a series of reactions during cholesterol synthesis, 3 Molecules of ATP are used to make isopentenyl pyrophosphate.
c. Squalene is a 10-carbon intermediate used in cholesterol synthesis.
d. Oxidoreductase cyclizes lanosterol to make farnesyl pyrophosphate

Answer 114

b. In a series of reactions during cholesterol synthesis, 3 Molecules of ATP are used to make isopentenyl pyrophosphate.

Question 115

Please choose the true statement:

a. Acetyl CoA carboxylase catalyzes the committed step in fatty acid beta-oxidation.
b. NADPH reduces substrates in the reductive synthetic reactions of fatty acid beta-oxidation.
c. NADPH is produced in the non-oxidative pentose phosphate pathway.
d. Glutathione is important for reducing peroxides and other reactive oxygen species.

Answer 115

d. Glutathione is important for reducing peroxides and other reactive oxygen species.

Question 116

Glucose 6-Phosphate dehydrogenase catalyzes the first committed step of the oxidative pentose phosphate pathway.

a. True
b. False

Answer 116

a. True

Question 117

Rapidly dividing cells that need ribose 5-P for nucleotide synthesis but not NADPH, would use the oxidative pathway only and would not use the non-oxidative pentose pathway.

a. True
b. False

Answer 117

b. False

Question 118

Deficiency of glucose 6-phosphate dehydrogenase is often sub-clinical and becomes noticeable when a person has hemolytic anemia after oxidative challenge that can be a result of:

a. Antibiotics
b. Anitmalarials
c. Infection
d. Eating certain foods like fava beans
e. All of the above

Answer 118

e. All of the above

Question 119

During β-oxidation of odd-numbered fatty acids, propionyl-CoA is catabolized to succinyl CoA in a series of reactions that require Vitamin B12.

a. True
b. False

Answer 119

a. True

Question 120

Isoprene units are used for the construction of all of the following EXCEPT:

a. Membrane lipids in archaea
b. Sphingomyelin in eukaryotes
c. Cholesterol
d. Lipid anchors for membrane proteins

Answer 120

b. Sphingomyelin in eukaryotes

Question 121

Please choose the true statement regarding phosphatidate. Phosphatidate…

a. is an intermediate in cholesterol synthesis.
b. is an intermediate in sphingolipid synthesis.
c. is an intermediate in the synthesis of triacylglycerol.
d. All of the above are true.

Answer 121

c. is an intermediate in the synthesis of triacylglycerol.

Question 122

Dipalmitoyl phosphatidylcholine can be deficient in preterm infants and lead to respiratory distress.

a. True
b. False

Answer 122

a. True

Question 123

Please choose the false answer regarding the response of liver cells to glucagon: Glucagon promotes an …

a. increase in the activity of glycogen synthase
b. increase in the activity of glycogen phosphorylase kinase
c. increase in the release of free glucose
d. increase in the intracellular concentrations of cAMP

Answer 123

a. increase in the activity of glycogen synthase

Question 124

Chylomicrons are produced in the liver and contain more triacylglycerol than cholesterol or cholesterol

esters.
a. True
b. False

Answer 124

b. False

Question 125

Triacylglycerol must be catabolized to monoacylglycerol and two fatty acids to pass through the cell
membrane and enter cells.
a. True
b. False

Answer 125

a. True

Question 126

In which of the following processes can glycerol be used as an intermediate?

a. Triacylglycerol synthesis
b. Glycolysis
c. Phospholipid synthesis
d. Gluconeogenesis
e. All the above
f. All but d

Answer 126

e. All the above

Question 127

Triacylglycerol yields a greater quantity of ATP per gram than glycogen.

a. True
b. False

Answer 127

a. True

Question 128

Linolenate and linoleate are polyunsaturated essential fatty acids that must be obtained from the diet.

a. True
b. False

Answer 128

a. True

Question 129

Please choose the true statement:

a. Long saturated fatty acids have lower melting temperatures than shorter unsaturated fatty acids.
b. Humans synthesize odd numbered fatty acids.
c. Humans synthesize unsaturated fatty acids in which double bonds are in the trans configuration.
d. 16 and 18 carbon fatty acids are the most common fatty acids made in animals.

Answer 129

d. 16 and 18 carbon fatty acids are the most common fatty acids made in animals.

Question 130

please write out the reaction, including the reactants, products and enzyme for the following:
the first committed step of fatty acid synthesis

Answer 130

Acetyl CoA + CO2 (as HCO2-) Yields Malonyl CoA + ADP + Pi + H+

Question 131

please write out the reaction, including the reactants, products and enzyme for the following:
The forward reaction of the TCA cycle in which succinate is a reactant; don’t forget the electron carrier.

Answer 131

Succinate + FAD Yields Fumarate +FADH2

Question 132

Please list all of the enzymes that catalyze reactions in which NADH or FADH2 are produced in the TCA cycle

Answer 132

Isocitrate dehydrogenase
Alpha-ketoglutarate
Succinate dehydrogenase
Malate dehydrogenase

Question 133

In the malate-aspartate shuttle, what is the fate of the oxaloacetate that is made in the mitochondrion? Please choose from: oxidation, reduction, transamination, hydrolysis, hydration.

Answer 133

Transamination

Question 134

Please write this reaction out including all reactants, products, and the enzyme catalyst (in the mitochondrion):

Answer 134

Oxaloacetate + Gluatmate Yields Alpha-Ketoglutarate + Aspartate

Question 135

How many NADH are produced by beta-oxidation of a 18-carbon saturated fatty acid?

Answer 135

8

Question 136

β-N-acetylhexoseminidase is defective or absent in children with a fatal, neurodegenerative disease that is caused by a recessive genetic mutation. What is this disease?

Answer 136

Tay-Sach’s Disease

Question 137

In a cell that required a great deal of energy and fatty acid synthesis, which of the pathways, i-v, would be active in addition to fatty acid synthesis?

i. Oxidative reactions of the pentose phosphate pathway.
ii. Glycolysis
iii. Non-oxidative reactions of the pentose phosphate pathway
iv. The TCA cycle and oxidative phosphorylation.
v. Gluconeogenesis

a. i, ii, iv
b. i ii, iii, iv
c. i, iv, v
d. iii, iv,v

Answer 137

b. i ii, iii, iv

Question 138

Which pathways, i or iii, would be active in rapidly dividing cells, like tumor cells, which require nucleic acids for DNA synthesis?

i. Oxidative reactions of the pentose phosphate pathway.
ii. Glycolysis
iii. Non-oxidative reactions of the pentose phosphate pathway
iv. The TCA cycle and oxidative phosphorylation.
v. Gluconeogenesis

a. i
b. iii
c. Both i and iii

Answer 138

b. iii. Fructose 6-P will be used and the non-oxidative PPP will be driven backwards

Question 139

The committed step in the conversion of glucose-6-phosphate to ribose-5-phosphate is catalyzed by glucose-6-phosphate dehydrogenase.

a. True
b. False

Answer 139

a. True

Question 140

The cofactor thiamine pyrophosphate serves what purpose?

a. acyl transferase reactions, in which the TPP carbanion makes a nucleophilic attack on the acyl group to be transferred
b. methylation and 1-carbon transfers
c. mutase reactions, in which the cobalt metal is reduced during radical formation
d. epimerization reactions in which the carbocation dissipates the negative charge forming in the transition state.

Answer 140

a. acyl transferase reactions, in which the TPP carbanion makes a nucleophilic attack on the acyl group to be transferred

Question 141

During ATP synthesis, a proton gradient is used to protonate an aspartate residue in the c-ring of Fo.

a. True
b. False

Answer 141

a. True

Question 142

Glycogen is synthesized when:

a. insulin levels are low
b. glycogen phosphorylase is deactivated by dephosphorylation
c. in response to the global effectors, epinephrine and glucagon
d. None of the above

Answer 142

b. glycogen phosphorylase is deactivated by dephosphorylation

Question 143

The oxidative portion of the pentose phosphate pathway produces 3, 4, 5, 6 and 7 carbon sugars.

a. True
b. False

Answer 143

b. False

This occurs in the non-oxidative PPP

Question 144

Ketone bodies are:

a. derivatives of Acetyl CoA used for energy production in heart muscle and also are used in the brain when carbohydrates stores are low or glucose metabolism is impaired
b. macromolecular assemblages of lipids and lipoproteins used for lipid transport in the blood
c. carbonyl-rich molecules stored in the liver as an alternative to triglycerides when fatty acid anabolism is not fully functional
d. specialized carbohydrate complexes that are accumulated in diabetics instead of glycogen

Answer 144

a. derivatives of Acetyl CoA used for energy production in heart muscle and also are used in the brain when carbohydrates stores are low or glucose metabolism is impaired

Question 145

The pentose phosphate pathway is:

a. the source of ribose 5-phosphate for nucleotide synthesis
b. the primary source of NADH for anabolic pathways
c. the primary source of NADP+ for anabolic pathways
d. a major source of ATP under dietary carbohydrate limitation

Answer 145

a. the source of ribose 5-phosphate for nucleotide synthesis

Question 146

Odd carbon fatty acids produce propionyl-CoA, rather than the 2 carbon units, acetyl-CoA, with each turn of the beta oxidation cycle.

a. True
b. False

Answer 146

b. False

Question 147

In diabetics, excess oxaloacetate is metabolized to ketone bodies.

a. True
b. False

Answer 147

b. False

There is no excess OAA

Question 148

Which of the following is false regarding regulation of fatty acid synthesis:

a. Citrate is an allosteric activator of acetyl-CoA carboxylase by enhancing the formation of the active polymer
b. Palmitate can reverse the activation by citrate, by promoting acetyl-CoA carboxylase fiber disassembly.
c. Palmitate promotes citrate export from the mitochondrial matrix
d. Citrate activates both phosphorylated and non-phosphorylated acetyl-CoA carboxylase

Answer 148

c. Palmitate promotes citrate export from the mitochondrial matrix

Question 149

Which of the following is true about fatty acid synthesis.

a. these reactions occur in the mitochondria
b. no ACP intermediates are used
c. the formation of malonyl-CoA from acetyl CoA and HCO3- in an ATP dependent reaction is the first committed step
d. the formation of acetyl Co A from Malonyl-CoA by decarboxylation is the committed step
e. several anabolic reactions are reversed during fatty acid catabolism by allowing the same enzymes to catalyze the reverse reactions

Answer 149

c. the formation of malonyl-CoA from acetyl CoA and HCO3- in an ATP dependent reaction is the first committed step

Question 150

Please list the enzymes that catalyze reactions in which NADH and FADH2 are produced in the TCA cycle.

Answer 150

Isocitrate DH - NADH
Alpha-ketoglutarate DHC - NADH
Succinate DH - FADH2
Malate DH - NADH

Question 151

Please write out the forward reaction that results in the production of CoEnzyme A in the TCA Cycle

Answer 151

Succinyl CoA + GDP + Pi yields succinate + CoA + GTP

This reaction is catalyzed by succinyl CoA synthetase (named for the reverse reaction)

Question 152

Please describe the deficiency, the symptoms and the underlying reason for Favism.

Answer 152

Deficiency: Glucose 6-P DH (G6PD)

Symptoms: Hemolytic anemia

Underlying reasons for the symptoms: Reduced G6PD activity lowers the amount of glutathione in the reduced state in RBCs. Because of this, more components of RBCs are left oxidized, which destabilizes the RBS membrane, and this RBCs are more prone to rupture

Question 153

Please state how many moles of ATP are produced from one mole of glucose… when the glycerol-phosphate shuttle is being used

Answer 153

30

Question 154

Please state how many moles of ATP are produced from one mole of glucose…
when the maleate-aspatrate shuttle is used

Answer 154

32

Question 155

Why is there a difference in the two numbers when using the glycerol-phosphate shuttle and the malate-aspartate shuttle.

Answer 155

Use of the glycerol phosphate shuttle results in the production of NADH2 from NADH. Thus 2 moles of ATP are lost overall 1(1.5 ATP/Po) rather than 2(2.5 ATP/Po)

Question 156

state which Complex in the ETC (I-IV) is directly affected by CO

Answer 156

IV

Question 157

state which Complex in the ETC (I-IV) is directly affected by antimycin

Answer 157

III

Question 158

state which Complex in the ETC (I-IV) is directly affected by H2S

Answer 158

IV

Question 159

state which Complex in the ETC (I-IV) is directly affected by amytal

Answer 159

I

Question 160

Please list in order all electron carriers used when the glycerol phosphate shuttle is used to bring reducing equivalents into the mitochondrion and those electrons travel through the electron transport chain.

Answer 160

The electrons are passed to Ubiquinone to make ubiquinol. The next carrier is complex III, then cytochrome C, then complex IV, and finally oxygen

Question 161

Please identify the membrane-bound carriers in complex III and IV. List the mobile carriers and state where they are located.

Answer 161

Ubiquinone- the inner mitochondrial membrane, cytochrome C - the mitochondrial inter membrane space

Question 162

What is true regarding Respiratory Distress Syndrome (RDS):

a. Is a result of insufficient formation of dipalmitoyl phosphatidylcholine
b. Is a result of insufficient surfactant that coats the lung surface
c. Is a result of the lungs being too difficult to expand due to increased surface tension .
d. all the above are true

Answer 162

d. all the above are true

Question 163

Sphingolipids are an important class of membrane lipids found in all tissues, but with highest concentrations in what location?

Answer 163

The central nervous system

Question 164

Fatty acid synthesis, and cholesterol synthesis occur in the cytosol, while beta-oxidation of fatty acids, ketone body formation and the TCA cycle all happen in the mitochondrial matrix.

a. True
b. False

Answer 164

a. True

Question 165

Which of the following is incorrect regarding fatty acid metabolism?

a. Maximum length of fatty acids made by fatty acid synthase is 16C.
b. Desaturation of fatty acids occurs in the mitochondrion.
c. Fatty acid synthesis requires malonyl CoA as a donor molecule of acetyl groups.
d. During fatty acid synthesis, the addition of acetyl CoA is driven by CO2 release

Answer 165

b. Desaturation of fatty acids occurs in the mitochondrion.

Question 166

Please chose the True statement:

a. In catabolism of odd-numbered fatty acids, propionyl CoA is converted to an intermediate of the TCA cycle.
b. in the catabolism of odd-numbered fatty acids, methylmalonyl CoA mutase catalyzes an intramolecular rearrangement that requires vitamin B12.
c. In the degradation of propionyl Co A, heterolytic cleavage of the coordination between cobalt and the 5´-deoxyadenosyl unit allows radical formation.
d. All the above are correct
e. Only a and b are correct
f. Only b and c are correct

Answer 166

e. Only a and b are correct

In the degradation of propionyl Co A, homolytic cleavage of the coordination between cobalt and the 5´-deoxyadenosyl unit allows radical formation. This is true when it is homolytic.

Question 167

Please choose the correct statement:

a. Glycogen is a highly branched polymer of glucose with branch points approximately every 10 glucosyl units.
b. Straight chains of glycogen have α-1,6 linkage
c. Branch points have α-1,4 linkage.
d. Glycogenin, is a necessary initiator primer molecule, to which glucosyl residues attach
e. All the above are correct
f. Only a and d are correct
g. a, b and c are correct.

Answer 167

f. Only a and d are correct

Linkages are revered in b and c

Question 168

Please choose the true Statement:

a. Glycogen phosphorylase catalyzes the phosphorolysis of alpha 1,6 glycosidic bonds.
b. Glycogen phosphorylase is down-regulated by phosphorylation
c. Glycogen phosphorylase is dephosphorylated in response to insulin
d. There are no true answers here.
e. Only b and d are true

Answer 168

c. Glycogen phosphorylase is dephosphorylated in response to insulin