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Revision Flashcards

1
Q

The acetyl CoA formed on beta-oxidation of all long chain fatty acids is metabolized under normal circumstances to ___________.

A

CO2 and water

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2
Q

What allows electron transport to proceed without ATP synthesis?

A

An uncoupler of oxidative phosphorylation such as dinitrophenol

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3
Q 
During each cycle of B-oxidation of fatty acid, all the following compounds are generated except?
A. Acyl CoA
B. H2O
C. FAD
D. NADH
A

H2O

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4
Q

The refilling of TCA cycle intermediates is frequently
dependant upon which of the following cofactors?
(A) Niacin
(B) Ribofl avin
(C) Carnitine
(D) Pyridoxal phosphate
(E) Lipoate

A

Pyridoxal phosphate

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5
Q 
Which of the following is a precursor of gluconeogenesis?
A. Glycogen
B. Lactate
C. Galactose
D. Glucose-1-phosphate
A

lactate

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6
Q

What is required for making glycogen following a carbohydrate rich meal?

A

glycogen phosphorylase

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7
Q

Electron transport and phosphorylation can be uncoupled by compounds that increase the permeability of the inner mitochondrial membrane to?

A

protons

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8
Q 
The energy yield from the complete oxidation of acetyl-CoA to carbon dioxide is which of the following in terms of high-energy bonds formed?
A. 10
B. 14
C. 8
D. 12
A

10

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9
Q 
All of the following are members of the electron transport chain except?
A. FAD
B. Ubiquinone
C. NAD
D. Carnitine
A

carnitine

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10
Q

In pyruvate kinase deficiency the RBCs rupture because of low amount of?

A

ATP

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11
Q 
Which of the following is a low affinity glucose transporter?
A. GLUT-2
B. GLUT-3
C. GLUT-1
D. GLUT-4
A

GLUT-2

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12
Q

Beta-oxidation of odd-carbon fatty acid chain produces?

A

Malonyl CoA

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13
Q

Long chain fatty acyl CoA esters are transported across the mitochondrial membrane by?

A

Carnitine

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14
Q

In glycogenolysis, which enzyme will convert glucose-1-phosphate to glucose-6-phosphate?

A

phosphoglucomutase

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15
Q

A 20-year old male presents with severe muscle cramps. He is found to have muscle glycogen phosphorylase deficiency (McArdle’s disease). This deficient enzyme degrades glycogen to produce?

A

glucose-1-phosphate

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16
Q

Given that the standard free energy change for the hydrolysis of ATP is -7.3 K cal/mol and that for the hydrolysis of Glucose-6-phosphate is -3.3 Kcal/mol, the standard free energy for the phosphorylation of glucose is Glucose + ATP -> Glucose-6-Phosphate + ADP

A

+4.0 Kcal/mol

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17
Q 
All of the following compounds are intermediates of TCA cycle except  
(A) Maleate  
(B) Pyruvate  
(C) Oxaloacetate  
(D) Fumarate
A

Pyruvate

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18
Q 
The energy yield from complete oxidation of products generated by second reaction cycle of β-oxidation of palmitoyl CoA will be  
(A) 5 ATP  
(B) 12 ATP  
(C) 17 ATP  
(D) 34 ATP
A

34 ATP

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19
Q

If the ΔG0’ of the reaction A -> B is -40 kJ/mol, under standard conditions, which of the following is correct?
A. ΔG0’ will not occur spontaneously
B. the reaction is at equilibrium
C. ΔG0’ will proceed spontaneously from left to right
D. ΔG0’ will equal to zero at equilibrium

A

ΔG0’ will proceed spontaneously from left to right

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20
Q 
2,3-bisphosphoglycerate is synthesized in?
A. Cardiac muscle
B. Skeletal muscle
C. Red blood cells
D. Liver
A

Red blood cells

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21
Q 
Which of the following enzymes is not present in muscles?
A. Hexokinase
B. Lactate dehydrogenase
C. Glycogen synthase
D. Glucose-6-phosphatase
A

Glucose-6-phosphatase

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22
Q

The committed and the rate limiting step of glycolysis is cataylsed by?

A

Phosphofructokinase I

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23
Q 
Reduced glutathione functions in RBCs to
A. Produce NADH
B. Produce NADPH
C. Reduce oxidizing agents such as H2O2
D. Reduce methemoglobin to hemoglobin
A

Reduce oxidizing agents such as H2O2

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24
Q 
Glycolysis in erythrocytes produces pyruvate that is further metabolised to
A. Acetyl CoA
B. CO2
C. Lactate
D. Ethanol
A

lactate

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25
Q

The free energy change, ΔG
A. Is equal to zero at equilibrium
B. Is directly proportional to the standard free energy change
C. Can only be calculated when the reacts and products are present at 1mol/1 concentrations
D. Is equal to -RT in keq

A

Is equal to zero at equilibrium

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26
Q 
Which of the following hormone inhibits gluconeogenesis?
A. Epinephrine
B. Glucagon
C. Cortisone
D. Insulin
A

insulin

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27
Q 
Vitamins are
(A) Accessory food factors
(B) Generally synthesized in the body
(C) Produced in endocrine glands
(D) Proteins in nature
A

Accessory food factors

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28
Q 
Vitamin A or retinal is a
(A) Steroid
(B) Polyisoprenoid compound containing a cyclohexenyl ring
(C) Benzoquinone derivative
(D) 6-Hydroxychromane
A

Polyisoprenoid compound containing a cyclohexenyl ring

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29
Q 
β-Carotene, precursor of vitamin A, is
oxidatively cleaved by
(A) β-Carotene dioxygenase
(B) Oxygenase
(C) Hydroxylase
(D) Transferase
A

β-Carotene dioxygenase

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30
Q

Retinal is reduced to retinol in intestinalmucosa by a specific retinaldehyde reductase utilising
(A) NADPH + H+ (B) FAD
(C) NAD (D) NADH + H+

A

NADPH + H+

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31
Q 
Preformed Vitamin A is supplied by
(A) Milk, fat and liver
(B) All yellow vegetables
(C) All yellow fruits
(D) Leafy green vegetables
A

Milk, fat and liver

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32
Q 
Fat soluble vitamins are
(A) Soluble in alcohol
(B) one or more Propene units
(C) Stored in liver
(D) All these
A

All these

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33
Q 
Retinol is transported in blood bound to
(A) Aporetinol binding protein
(B) α2-Globulin
(C) β-Globulin
(D) Albumin
A

Aporetinol binding protein

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34
Q 
One manifestation of vitamin A deficiency is
(A) Painful joints
(B) Night blindness
(C) Loss of hair
(D) Thickening of long bones
A

Night blindness

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35
Q 
Deficiency of Vitamin A causes
(A) Xeropthalmia
(B) Hypoprothrombinemia
(C) Megaloblastic anemia
(D) Pernicious anemia
A

Xeropthalmia

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36
Q

An important function of vitamin A is
(A) To act as coenzyme for a few enzymes
(B) To play an integral role in protein synthesis
(C) To prevent hemorrhages
(D) To maintain the integrity of epithelial tissue

A

To maintain the integrity of epithelial tissue

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37
Q

Retinal is a component of
(A) Iodopsin (B) Rhodopsin
(C) Cardiolipin (D) Glycoproteins

A

Rhodopsin

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38
Q

Retinoic acid participates in the synthesis of
(A) Iodopsin (B) Rhodopsin
(C) Glycoprotein (D) Cardiolipin

A

Glycoprotein

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39
Q

On exposure to light rhodopsin forms
(A) All trans-retinal (B) Cis-retinal
(C) Retinol (D) Retinoic acid

A

All trans-retinal

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40
Q 
Vitamin D absorption is increased in
(A) Acid pH of intestine
(B) Alkaline pH of intestine
(C) Impaired fat absorption
(D) Contents of diet
A

Acid pH of intestine

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41
Q 
The most potent Vitamin D metabolite is
(A) 25-Hydroxycholecalciferol
(B) 1,25-Dihydroxycholecalciferol
(C) 24, 25-Dihydroxycholecalciferol
(D) 7-Dehydrocholesterol
A

1,25-Dihydroxycholecalciferol

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42
Q

A poor source of Vitamin D is
(A) Egg (B) Butter
(C) Milk (D) Liver

A

Milk

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43
Q

Richest source of Vitamin D is
(A) Fish liver oils (B) Margarine
(C) Egg yolk (D) Butter

A

Fish liver oils

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44
Q 
Calcitriol synthesis involves
(A) Both liver and kidney
(B) Intestine
(C) Adipose tissue
(D) Muscle
A

Both liver and kidney

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45
Q

Insignificant amount of Vitamin E is present in
(A) Wheat germ oil (B) Sunflower seed oil
(C) Safflower seed oil (D) Fish liver oil

A

Fish liver oil

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46
Q 
The activity of tocopherols is destroyed by
(A) Commercial cooking
(B) Reduction
(C) Conjugation
(D) All of these
A

Commercial cooking

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47
Q 
The requirement of vitamin E is increased with greater intake of
(A) Carbohydrates
(B) Proteins
(C) Polyunsaturated fat
(D) Saturated fat
A

Polyunsaturated fat

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48
Q

Vitamin E reduces the requirement of
(A) Iron (B) Zinc
(C) Selenium (D) Magnesium

A

Selenium

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49
Q

The most important natural antioxidant is
(A) Vitamin D (B) Vitamin E
(C) Vitamin B12 (D) Vitamin K

A

Vitamin E

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50
Q

Tocopherols prevent the oxidation of
(A) Vitamin A (B) Vitamin D
(C) Vitamin K (D) Vitamin C

A

Vitamin A

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51
Q

Creatinuria is caused due to the deficiency of vitamin
(A) A (B) K
(C) E (D) D

A

E

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52
Q

Vitamin K is found in
(A) Green leafy plants (B) Meat
(C) Fish (D) Milk

A

Green leafy plants

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53
Q 
Function of Vitamin A:
(A) Healing epithelial tissues
(B) Protein synthesis regulation
(C) Cell growth
(D) All of these
A

All of these

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54
Q

Vitamin synthesized by bacterial in the intestine is
(A) A (B) C
(C) D (D) K

A

K

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55
Q

Vitamin K is involved in posttranslational
modification of the blood clotting factors
by acting as cofactor for the enzyme:
(A) Carboxylase (B) Decarboxylase
(C) Hydroxylase (D) Oxidase

A

Carboxylase

56
Q 
Vitamin K is a cofactor for
(A) Gamma carboxylation of glutamic acid residue
(B) β-Oxidation of fatty acid
(C) Formation of γ-amino butyrate
(D) Synthesis of tryptophan
A

Gamma carboxylation of glutamic acid residue

57
Q

The vitamin which would most likely become deficient in an individual who develop a completely carnivorous life style is
(A) Thiamin (B) Niacin
(C) Vitamin C (D) Cobalamin

A

Vitamin C

58
Q

In human body highest concentration of ascorbic acid is found in
(A) Liver (B) Adrenal cortex
(C) Adrenal medulla (D) Spleen

A

Adrenal cortex

59
Q

The vitamin required for the formation of
hydroxyproline (in collagen) is
(A) Vitamin C (B) Vitamin A
(C) Vitamin D (D) Vitamin E

A

Vitamin C

60
Q

Both Wernicke’s disease and beriberi can be reversed by administrating
(A) Retinol (B) Thiamin
(C) Pyridoxine (D) Vitamin B12

A

Thiamin

61
Q

The Vitamin B1 deficiency causes
(A) Ricket (B) Nyctalopia
(C) Beriberi (D) Pellagra

A

Beriberi

62
Q

Concentration of pyruvic acid and lactic acid in blood is increased due to deficiency of the vitamin
(A) Thiamin (B) Riboflavin
(C) Niacin (D) Pantothenic acid

A

Thiamin

63
Q

Increased glucose consumption increases the dietary requirement for
(A) Pyridoxine (B) Niacin
(C) Biotin (D) Thiamin

A

Thiamin

64
Q 
Riboflavin is a coenzyme in the reaction catalysed by the enzyme
(A) Acyl CoA synthetase
(B) Acyl CoA dehydrogenase
(C) β-Hydroxy acyl CoA
(D) Enoyl CoA dehydrogenase
A

Acyl CoA dehydrogenase

65
Q 
Riboflavin deficiency causes
(A) Cheilosis
(B) Loss of weight
(C) Mental deterioration
(D) Dermatitis
A

Cheilosis

66
Q

Pellagra is caused due to the deficiency of
(A) Ascorbic acid (B) Pantothenic acid
(C) Pyridoxine (D) Niacin

A

Niacin

67
Q

Deficiency of vitamin B6 may occur in
(A) Obese person (B) Thin person
(C) Alcoholics (D) Diabetics

A

Alcoholics

68
Q

Biotin is a coenzyme of the enzyme
(A) Carboxylase (B) Hydroxylase
(C) Decarboxylase (D) Deaminase

A

Carboxylase

69
Q 
A cofactor required in oxidative decarboxylation of pyruvate is
(A) Lipoate
(B) Pantothenic acid
(C) Biotin
(D) Para aminobenzoic acid
A

Lipoate

70
Q 
A deficiency of vitamin B12 causes
(A) Beri-Beri
(B) Scurvy
(C) Pernicious anemia
(D) Ricket
A

Pernicious anemia

71
Q 
Folate as a coenzyme is involved in the transfer and utilization of
(A) Amino group
(B) Hydroxyl group
(C) Single carbon moiety
(D) Amido group
A

Single carbon moiety

72
Q 
Folate deficiency causes
(A) Microcytic anemia
(B) Hemolytic anemia
(C) Iron deficiency anemia
(D) Megaloblastic anemia
A

Megaloblastic anemia

73
Q

Thiamin deficiency includes
(A) Mental depression (B) Fatigue
(C) Beriberi (D) All of these

A

All of these

74
Q 
FAD is a coenzyme for
(A) Succinate dehydrogenase
(B) Glycerol-3-phosphate dehydrogenase
(C) Sphingosine reductase
(D) All of these
A

All of these

75
Q

NADP is required as a coenzyme in
(A) Glycolysis (B) Citric acid cycle
(C) HMP shunt (D) Gluconeogenesis

A

HMP shunt

76
Q

Pantothenic acid contains an amino acid which is
(A) Aspartic acid (B) Glutamic acid
(C) β-Alanine (D) β-Aminoisobutyric acid

A

β-Alanine

77
Q

The following is required for the formation of coenyzme A:
(A) ATP (B) GTP
(C) CTP (D) None of these

A

ATP

78
Q 
Pyridoxal phosphate is a coenzyme for
(A) Glycogen synthetase
(B) Phosphorylase
(C) Both (A) and (B)
(D) None of these
A

Phosphorylase

79
Q 
Vitamin B12 is
(A) Not stored in the body
(B) Stored in bone marrow
(C) Stored in liver
(D) Stored in RE cells
A

Stored in liver

80
Q

A vitamin which can be synthesized by human beings is
(A) Thiamin (B) Niacin
(C) Folic acid (D) Cyanocobalamin`

A

Niacin

81
Q 
Vitamin A is stored in the body in
(A) Liver
(B) Adipose tissue
(C) Reticuloendothelial cells
(D) All of these
A

Liver

82
Q

Rhodopsin contains opsin and
(A) 11-cis-retinal (B) 11-trans-retinal
(C) All-cis-retinal (D) All trans-retina

A

11-cis-retinal

83
Q

Anaerobiosis leads to lactate formation in muscle due to
which one of the following?
(A) Inhibiting hexokinase by glucose-6-phosphate
(B) Providing 2,3-bisphosphoglycerate for the phosphoglyceromutase reaction
(C) Inhibiting pyruvate kinase by pyruvate
(D) Providing substrate for glyceraldehyde-3-phosphate
dehydrogenase
(E) Inhibiting phosphofructokinase-1 by AMP

A

Providing substrate for glyceraldehyde-3-phosphate

dehydrogenase

84
Q

In muscle, under anaerobic conditions, the net synthesis
of ATP starting from one mole of glucose derived from
muscle glycogen is which one of the following?
(A) 1 mole of ATP
(B) 2 moles of ATP
(C) 3 moles of ATP
(D) 4 moles of ATP
(E) 5 moles of ATP

A

3 moles of ATP

85
Q

A 28-year-old male develops diabetes, as noted by constant, mildly elevated hyperglycemia. His father had
similar symptoms at the same age as did his paternal
grandmother. This patient is not obese, does not have
hypertension, does not have dyslipidemia, and does not
have antibodies directed against islet cells. This alteration in glucose homeostasis may be due to a mutation in
which of the following enzymes?
(A) Pancreatic glucokinase
(B) Pancreatic hexokinase
(C) Liver glucokinase
(D) Muscle hexokinase
(E) Intestinal glucokinase

A

Pancreatic glucokinase

86
Q 
Given that the standard free energy
change (∆G°) for the hydrolysis of ATP is
–7.3 K cal/mol and that for the hydrolysis
of Glucose 6-phosphate is –3.3 Kcal/mol,
the ∆G° for the phosphorylation of
glucose is Glucose + ATP → Glucose 6–
Phosphate + ADP.
(A) –10.6 Kcal/mol (B) –7.3 Kcal/mol
(C) –4.0 Kcal/mol (D) +4.0 Kcal/mo
A

–4.0 Kcal/mol

87
Q

At low blood glucose concentration, brain
but not liver will take up glucose. It is due
to the
(A) Low Km of hexokinase
(B) Low Km of glucokinase
(C) Specificity of glucokinase
(D) Blood brain barrier

A

Low Km of hexokinase

88
Q

In the reaction below, Nu TP stands for
NuTP + glucose → Glucose 6–Phosphate + NuDP.
(A) ATP (B) CTP
(C) GTP (D) UTP

A

ATP

89
Q 
In the glycolytic pathway, enolpyruvate is converted to ketopyruvate by
(A) Pyruvate kinase
(B) Phosphoenolpyruvate
(C) Pyruvate dehydrogenase
(D) Spontaneously
A

Spontaneously

90
Q 
In erythrocytes, 2, 3-biphosphoglycerate
is derived from the intermediate:
(A) Glyeraldehyde-3-phosphate
(B) 1, 3-Biphosphoglycerate
(C) 3-Phosphoglycerate
(D) 2-Phosphoglycerate
A

1, 3-Biphosphoglycerate

91
Q

2, 3-Biphosphoglycerate in high concentrations, combines with hemoglobin, causes
(A) Displacement of the oxyhemoglobin dissociation curve to the left
(B) Displacement of the oxyhemoglobin dissociation curve to the right
(C) No change in oxy hemoglobin dissociation curve
(D) Increased affinity for oxygen

A

Displacement of the oxyhemoglobin

dissociation curve to the right

92
Q 
Erythrocytes under normal conditions and
microorganisms under anaerobic conditions may accumulate
(A) NADPH
(B) Pyruvate
(C) Phosphoenolpyruvate
(D) Lactate
A

Lactate

93
Q

Enzymes leading to the high energy phosphorylation of substrates during glycolysis include which of the following?
(A) Phosphoglycerate kinase
(B) Enolase
(C) Pyruvate Kinase
(D) Glyceraldehyde-3-phosphate dehydrogenase

A

Glyceraldehyde-3-phosphate dehydrogenase

94
Q

Phosphofructokinase key enzyme in
glycolysis is inhibited by
(A) Citrate and ATP (B) AMP
(C) ADP (D) TMP

A

Citrate and ATP

95
Q 
Hexokinase is inhibited in an allosteric manner by
(A) Glucose-6-Phosphate
(B) Glucose-1-Phosphate
(C) Fructose-6-phosphate
(D) Fructose-1, 6-biphosphate
A

Glucose-6-Phosphate

96
Q

The net number of ATP formed per mole of glucose in anaerobic glycolysis is
(A) 1 (B) 2
(C) 6 (D) 8

A

2

97
Q 
Pyruvate dehydrogenase a multienzyme complex is required for the production of
(A) Acetyl-CoA
(B) Lactate
(C) Phosphoenolpyruvate
(D) Enolpyruvate
A

Acetyl-CoA

98
Q 
Dietary deficiency of thiamin inhibits the
activity of the enzyme:
(A) Pyruvate kinase
(B) Pyruvate dehydrogenase
(C) Phosphofructokinase
(D) Enolase
A

Pyruvate dehydrogenase

99
Q

Pyruvate dehydrogenase activity is inhibited by
(A) Mercury (B) Zinc
(C) Calcium (D) Sodium

A

Mercury

100
Q

All the enzymes of glycolysis pathway are found in
(A) Extramitochondrial soluble fraction of the cell
(B) Mitochondria
(C) Nucleus
(D) Endoplasmic reticulum

A

Extramitochondrial soluble fraction of the cell

101
Q

Most major metabolic pathways are considered mainly either anabolic or catabolic. Which of the following pathway
is most correctly considered to be amphibolic?
(A) Citric acid cycle (B) Gluconeogenesis
(C) Lipolysis (D) Glycolysis

A

Citric acid cycle

102
Q

The enzymes of the citric acid cycle are located in
(A) Mitochondrial matrix
(B) Extramitochondrial soluble fraction of the cell
(C) Nucleus
(D) Endoplasmic reticulum

A

Mitochondrial matrix

103
Q

The initial step of the citric acid cycle is
(A) Conversion of pyruvate to acetyl-CoA
(B) Condensation of acetyl-CoA with oxaloacetate
(C) Conversion of citrate to isocitrate
(D) Formation of α -ketoglutarate catalysed by isocitrate dehydrogenase

A

Condensation of acetyl-CoA with oxaloacetate

104
Q

The substance which may be considered to play a catalytic role in citric acid cycle is
(A) Oxaloacetate (B) Isocitrate
(C) Malate (D) Fumarate

A

Oxaloacetate

105
Q 
An enzyme of the citric acid cycle also found outside the mitochondria is
(A) Isocitrate dehydrogenase
(B) Citrate synthetase
(C) α-Ketoglutarate dehydrogenase
(D) Malate dehydrogenase
A

α-Ketoglutarate dehydrogenase

106
Q

The reaction catalysed by α-ketoglutarate dehydrogenase in the citric acid cycle requires
(A) NAD (B) NADP
(C) ADP (D) ATP

A

NAD

107
Q 
In TCA cycle, oxalosuccinate is converted to α-ketoglutarate by the enzyme:
(A) Fumarase
(B) Isocitrate dehydrogenase
(C) Aconitase
(D) Succinase
A

Isocitrate dehydrogenase

108
Q

The enzyme a-ketoglutarate dehydrogenase in the citric acid cycle requires
(A) Lipoate (B) Folate
(C) Pyridoxine (D) Inositol

A

Lipoate

109
Q

The number of ATP molecules generated for each turn of the citric acid cycle is
(A) 8 (B) 12
(C) 24 (D) 38

A

12

110
Q

Oxidation of one molecule of glucose yields
(A) 12 ATP (B) 24 ATP
(C) 38 ATP (D) 38 ATP

A

38 ATP

111
Q

Which of the following intermediates of metabolism can be both a precursor and a product of glucose?
(A) Lactate (B) Pyruvate
(C) Alanine (D) Acetyl-CoA

A

Lactate

112
Q

Mitochondrial membrane is freely permeable to
(A) Pyruvate (B) Malate
(C) Oxaloacetate (D) Fumarate

A

Malate

113
Q

The coenzyme not involved in the
formation of acetyl-CoA from pyruvate is
(A) TPP (B) Biotin
(C) NAD (D) FAD

A

Biotin

114
Q

A carrier molecule in the citric acid cycle is
(A) Acetyl-CoA (B) Citrate
(C) Oxaloacetate (D) Malate

A

Oxaloacetate

115
Q 
The rate of citric acid cycle is controlled
by the allosteric enzyme:
(A) Aconitase
(B) Fumarase
(C) Fumarase
(D) Malate dehydrogenase
A

Fumarase

116
Q

Glucose 6-phosphate is converted to glucose 1-phosphate in a reaction catalysed by the enzyme phosphoglucomutase,
which is
(A) Phosphorylated
(B) Dephosphorylated
(C) Phosphorylated-dephosphorylated
(D) Phosphorylated-dephosphorylated-rephosphorylated

A

Phosphorylated-dephosphorylated-rephosphorylated

117
Q

In the synthesis of glycogen from glucose, the reversible step is
(A) Glucose → glucose 6-phosphate
(B) Glucose 6-phosphate → glucose 1-phosphate
(C) Glucose 1-phosphate → UDP glucose
(D) UDP glucose → glycogen

A

Glucose 6-phosphate → glucose 1-phosphate

118
Q 
The enzyme glucose-6-phosphatase
which catalyses the conversion of glucose
6-phosphate to glucose is not found in
(A) Liver (B) Muscle
(C) Intestine (D) Kidney
A

Muscle

119
Q

Allosteric activator of glycogen synthase is
(A) Glucose (B) Glucose-6-Phosphate
(C) UTP (D) Glucose-1-phosphate

A

Glucose-6-Phosphate

120
Q

The hormone activating the glycogen
synthase activity is
(A) Insulin (B) Glucagon
(C) Epinephrine (D) ACTH

A

insulin

121
Q

Action of glycogen synthase is inhibited by
(A) Insulin (B) Glucose
(C) Mg2+ (D) Cyclic AMP

A

Mg2+

122
Q 
Hemolytic anemia is caused by the deficiency of certain enzymes of the pentose phosphate pathway, the
principal enzyme involved is
(A) Glucose-6-phosphate dehydrogenase
(B) Aldolase
(C) Fructose 1, 6-bisphosphatase
(D) Phosphohexose isomerase
A

Glucose-6-phosphate dehydrogenase

123
Q 
The sites for gluconeogenesis are
(A) Liver and kidney
(B) Skin and pancreas
(C) Lung and brain
(D) Intestine and lens of eye
A

Liver and kidney

124
Q 
An enzyme involved in gluconeogenesis is
(A) Pyruvate kinase
(B) Pyruvate carboxylase
(C) Hexokinase
(D) Phosphohexose isomerase
A

Pyruvate carboxylase

125
Q 
The energy yield from the complete oxidation of acetyl CoA to carbon dioxide is which of the following in terms of high-energy bonds formed?
(A) 6
(B) 8
(C) 10
(D) 12
(E) 14
A

10

126
Q

Ethanol ingestion is incapable of supplying carbons
for gluconeogenesis. This is due to which of the following
(A) Ethanol is converted to acetone, and the carbons
are lost during exhalation
(B) Ethanol is lost directly in the urine
(C) Ethanol cannot enter the liver, where gluconeogenesis predominantly occurs
(D) Ethanol’s carbons are lost as carbon dioxide before
a gluconeogenic precursor can be generated
(E) Ethanol is converted to lysine, which is strictly a
ketogenic amino acid

A

Ethanol’s carbons are lost as carbon dioxide before

a gluconeogenic precursor can be generated

127
Q

A patient was diagnosed with a mitochondrial DNA
mutation that led to reduced complex I activity. This
patient would have difficulties in which of the following
electron transfers?
(A) Succinate to complex III
(B) Cytochrome c to complex IV
(C) Coenzyme Q to complex III
(D) Malate to coenzyme Q
(E) Coenzyme Q to oxygen

A

Malate to coenzyme Q

128
Q

A pair of farm workers in Mexico was spraying pesticide on crops when they both developed the following
severe symptoms: heavy, labored breathing, significantly
elevated temperature, and loss of consciousness. The
pesticide contained an agent that interfered with oxidative phosphorylation, which most closely resembled
which of the following known inhibitors?
(A) Oligomycin
(B) Atractyloside
(C) Cyanide
(D) Rotenone
(E) Dinitrophenol

A

Dinitrophenol

129
Q

The energy yield for the complete oxidation of citrate to six
carbon dioxides and water is which of the following?
(A) 15.0 moles of ATP per mole of citrate
(B) 17.5 moles of ATP per mole of citrate
(C) 20.0 moles of ATP per mole of citrate
(D) 22.5 moles of ATP per mole of citrate
(E) 25.0 moles of ATP per mole of citrate

A

22.5 moles of ATP per mole of citrate

130
Q

The refilling of TCA cycle intermediates is frequently
dependant upon which of the following cofactors?
(A) Niacin
(B) Riboflavin
(C) Carnitine
(D) Pyridoxal phosphate
(E) Lipoate

A

Pyridoxal phosphate

131
Q 
An inactivating mutation in which of the following
enzymes would lead to lactic acid accumulation in the
liver?
(A) Glucokinase
(B) Phosphofructokinase-1
(C) Cytoplasmic malate dehydrogenase
(D) Pyruvate kinase
(E) Glycerol-3-phosphate dehydrogenase
A

Cytoplasmic malate dehydrogenase

132
Q 
A patient has been diagnosed with abetalipoproteinemia. A possible deficiency in which of the following
vitamins could occur in this patient?
(A) Vitamin B1
(B) Vitamin B2
(C) Vitamin C
(D) Vitamin E
(E) Niacin
A

Vitamin E

133
Q 
A deficiency in which of the following vitamins will lead
to a functional folate deficiency?
(A) Thiamine
(B) Niacin
(C) Riboflavin
(D) B12
(E) Vitamin C
A

B12

134
Q

An individual has developed pancreatitis, and with it,
steatorrhea. The patient also reports problems with his
night vision, although visual acuity appears normal.
Another expected fi nding in this patient would be which
of the following?
(A) Nystagmus
(B) Easy bruising
(C) Dermatitis
(D) Loss of teeth
(E) Orange tonsils

A

Easy bruising

135
Q

A patient has had a series of blood clots, and has been
placed on warfarin to reduce such incidents. Warfarin
exerts its effect by blocking which of the following?
(A) Platelet biogenesis
(B) Phospholipid synthesis
(C) Clotting factor synthesis
(D) Vitamin E activity
(E) Formation of γ-carboxyglutamate

A

Formation of γ-carboxyglutamate

136
Q

A 42-year-old woman presents with tiredness and
lethargy. She has tingling in her hands and feet. Blood
work shows a macrocytic anemia, along with elevated
homocysteine levels. One would also expect to see elevated levels of which metabolite?
(A) Acetic acid
(B) Ketone bodies
(C) Methylmalonic acid
(D) Propionic acid
(E) Succinate

A

Methylmalonic acid

biochem (8 decks)

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