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
2
Q
What allows electron transport to proceed without ATP synthesis?
A
An uncoupler of oxidative phosphorylation such as dinitrophenol
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
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
5
Q
Which of the following is a precursor of gluconeogenesis? A. Glycogen B. Lactate C. Galactose D. Glucose-1-phosphate
A
lactate
6
Q
What is required for making glycogen following a carbohydrate rich meal?
A
glycogen phosphorylase
7
Q
Electron transport and phosphorylation can be uncoupled by compounds that increase the permeability of the inner mitochondrial membrane to?
A
protons
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
9
Q
All of the following are members of the electron transport chain except? A. FAD B. Ubiquinone C. NAD D. Carnitine
A
carnitine
10
Q
In pyruvate kinase deficiency the RBCs rupture because of low amount of?
A
ATP
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
12
Q
Beta-oxidation of odd-carbon fatty acid chain produces?
A
Malonyl CoA
13
Q
Long chain fatty acyl CoA esters are transported across the mitochondrial membrane by?
A
Carnitine
14
Q
In glycogenolysis, which enzyme will convert glucose-1-phosphate to glucose-6-phosphate?
A
phosphoglucomutase
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
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
17
Q
All of the following compounds are intermediates of TCA cycle except (A) Maleate (B) Pyruvate (C) Oxaloacetate (D) Fumarate
A
Pyruvate
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
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
20
Q
2,3-bisphosphoglycerate is synthesized in? A. Cardiac muscle B. Skeletal muscle C. Red blood cells D. Liver
A
Red blood cells
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
22
Q
The committed and the rate limiting step of glycolysis is cataylsed by?
A
Phosphofructokinase I
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
24
Q
Glycolysis in erythrocytes produces pyruvate that is further metabolised to A. Acetyl CoA B. CO2 C. Lactate D. Ethanol
A
lactate
25
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
Is equal to zero at equilibrium
26
```
Which of the following hormone inhibits gluconeogenesis?
A. Epinephrine
B. Glucagon
C. Cortisone
D. Insulin
```
insulin
27
```
Vitamins are
(A) Accessory food factors
(B) Generally synthesized in the body
(C) Produced in endocrine glands
(D) Proteins in nature
```
Accessory food factors
28
```
Vitamin A or retinal is a
(A) Steroid
(B) Polyisoprenoid compound containing a cyclohexenyl ring
(C) Benzoquinone derivative
(D) 6-Hydroxychromane
```
Polyisoprenoid compound containing a cyclohexenyl ring
29
```
β-Carotene, precursor of vitamin A, is
oxidatively cleaved by
(A) β-Carotene dioxygenase
(B) Oxygenase
(C) Hydroxylase
(D) Transferase
```
β-Carotene dioxygenase
30
Retinal is reduced to retinol in intestinalmucosa by a specific retinaldehyde reductase utilising
(A) NADPH + H+ (B) FAD
(C) NAD (D) NADH + H+
NADPH + H+
31
```
Preformed Vitamin A is supplied by
(A) Milk, fat and liver
(B) All yellow vegetables
(C) All yellow fruits
(D) Leafy green vegetables
```
Milk, fat and liver
32
```
Fat soluble vitamins are
(A) Soluble in alcohol
(B) one or more Propene units
(C) Stored in liver
(D) All these
```
All these
33
```
Retinol is transported in blood bound to
(A) Aporetinol binding protein
(B) α2-Globulin
(C) β-Globulin
(D) Albumin
```
Aporetinol binding protein
34
```
One manifestation of vitamin A deficiency is
(A) Painful joints
(B) Night blindness
(C) Loss of hair
(D) Thickening of long bones
```
Night blindness
35
```
Deficiency of Vitamin A causes
(A) Xeropthalmia
(B) Hypoprothrombinemia
(C) Megaloblastic anemia
(D) Pernicious anemia
```
Xeropthalmia
36
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
To maintain the integrity of epithelial tissue
37
Retinal is a component of
(A) Iodopsin (B) Rhodopsin
(C) Cardiolipin (D) Glycoproteins
Rhodopsin
38
Retinoic acid participates in the synthesis of
(A) Iodopsin (B) Rhodopsin
(C) Glycoprotein (D) Cardiolipin
Glycoprotein
39
On exposure to light rhodopsin forms
(A) All trans-retinal (B) Cis-retinal
(C) Retinol (D) Retinoic acid
All trans-retinal
40
```
Vitamin D absorption is increased in
(A) Acid pH of intestine
(B) Alkaline pH of intestine
(C) Impaired fat absorption
(D) Contents of diet
```
Acid pH of intestine
41
```
The most potent Vitamin D metabolite is
(A) 25-Hydroxycholecalciferol
(B) 1,25-Dihydroxycholecalciferol
(C) 24, 25-Dihydroxycholecalciferol
(D) 7-Dehydrocholesterol
```
1,25-Dihydroxycholecalciferol
42
A poor source of Vitamin D is
(A) Egg (B) Butter
(C) Milk (D) Liver
Milk
43
Richest source of Vitamin D is
(A) Fish liver oils (B) Margarine
(C) Egg yolk (D) Butter
Fish liver oils
44
```
Calcitriol synthesis involves
(A) Both liver and kidney
(B) Intestine
(C) Adipose tissue
(D) Muscle
```
Both liver and kidney
45
Insignificant amount of Vitamin E is present in
(A) Wheat germ oil (B) Sunflower seed oil
(C) Safflower seed oil (D) Fish liver oil
Fish liver oil
46
```
The activity of tocopherols is destroyed by
(A) Commercial cooking
(B) Reduction
(C) Conjugation
(D) All of these
```
Commercial cooking
47
```
The requirement of vitamin E is increased with greater intake of
(A) Carbohydrates
(B) Proteins
(C) Polyunsaturated fat
(D) Saturated fat
```
Polyunsaturated fat
48
Vitamin E reduces the requirement of
(A) Iron (B) Zinc
(C) Selenium (D) Magnesium
Selenium
49
The most important natural antioxidant is
(A) Vitamin D (B) Vitamin E
(C) Vitamin B12 (D) Vitamin K
Vitamin E
50
Tocopherols prevent the oxidation of
(A) Vitamin A (B) Vitamin D
(C) Vitamin K (D) Vitamin C
Vitamin A
51
Creatinuria is caused due to the deficiency of vitamin
(A) A (B) K
(C) E (D) D
E
52
Vitamin K is found in
(A) Green leafy plants (B) Meat
(C) Fish (D) Milk
Green leafy plants
53
```
Function of Vitamin A:
(A) Healing epithelial tissues
(B) Protein synthesis regulation
(C) Cell growth
(D) All of these
```
All of these
54
Vitamin synthesized by bacterial in the intestine is
(A) A (B) C
(C) D (D) K
K
55
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
Carboxylase
56
```
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
```
Gamma carboxylation of glutamic acid residue
57
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
Vitamin C
58
In human body highest concentration of ascorbic acid is found in
(A) Liver (B) Adrenal cortex
(C) Adrenal medulla (D) Spleen
Adrenal cortex
59
The vitamin required for the formation of
hydroxyproline (in collagen) is
(A) Vitamin C (B) Vitamin A
(C) Vitamin D (D) Vitamin E
Vitamin C
60
Both Wernicke’s disease and beriberi can be reversed by administrating
(A) Retinol (B) Thiamin
(C) Pyridoxine (D) Vitamin B12
Thiamin
61
The Vitamin B1 deficiency causes
(A) Ricket (B) Nyctalopia
(C) Beriberi (D) Pellagra
Beriberi
62
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
Thiamin
63
Increased glucose consumption increases the dietary requirement for
(A) Pyridoxine (B) Niacin
(C) Biotin (D) Thiamin
Thiamin
64
```
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
```
Acyl CoA dehydrogenase
65
```
Riboflavin deficiency causes
(A) Cheilosis
(B) Loss of weight
(C) Mental deterioration
(D) Dermatitis
```
Cheilosis
66
Pellagra is caused due to the deficiency of
(A) Ascorbic acid (B) Pantothenic acid
(C) Pyridoxine (D) Niacin
Niacin
67
Deficiency of vitamin B6 may occur in
(A) Obese person (B) Thin person
(C) Alcoholics (D) Diabetics
Alcoholics
68
Biotin is a coenzyme of the enzyme
(A) Carboxylase (B) Hydroxylase
(C) Decarboxylase (D) Deaminase
Carboxylase
69
```
A cofactor required in oxidative decarboxylation of pyruvate is
(A) Lipoate
(B) Pantothenic acid
(C) Biotin
(D) Para aminobenzoic acid
```
Lipoate
70
```
A deficiency of vitamin B12 causes
(A) Beri-Beri
(B) Scurvy
(C) Pernicious anemia
(D) Ricket
```
Pernicious anemia
71
```
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
```
Single carbon moiety
72
```
Folate deficiency causes
(A) Microcytic anemia
(B) Hemolytic anemia
(C) Iron deficiency anemia
(D) Megaloblastic anemia
```
Megaloblastic anemia
73
Thiamin deficiency includes
(A) Mental depression (B) Fatigue
(C) Beriberi (D) All of these
All of these
74
```
FAD is a coenzyme for
(A) Succinate dehydrogenase
(B) Glycerol-3-phosphate dehydrogenase
(C) Sphingosine reductase
(D) All of these
```
All of these
75
NADP is required as a coenzyme in
(A) Glycolysis (B) Citric acid cycle
(C) HMP shunt (D) Gluconeogenesis
HMP shunt
76
Pantothenic acid contains an amino acid which is
(A) Aspartic acid (B) Glutamic acid
(C) β-Alanine (D) β-Aminoisobutyric acid
β-Alanine
77
The following is required for the formation of coenyzme A:
(A) ATP (B) GTP
(C) CTP (D) None of these
ATP
78
```
Pyridoxal phosphate is a coenzyme for
(A) Glycogen synthetase
(B) Phosphorylase
(C) Both (A) and (B)
(D) None of these
```
Phosphorylase
79
```
Vitamin B12 is
(A) Not stored in the body
(B) Stored in bone marrow
(C) Stored in liver
(D) Stored in RE cells
```
Stored in liver
80
A vitamin which can be synthesized by human beings is
(A) Thiamin (B) Niacin
(C) Folic acid (D) Cyanocobalamin`
Niacin
81
```
Vitamin A is stored in the body in
(A) Liver
(B) Adipose tissue
(C) Reticuloendothelial cells
(D) All of these
```
Liver
82
Rhodopsin contains opsin and
(A) 11-cis-retinal (B) 11-trans-retinal
(C) All-cis-retinal (D) All trans-retina
11-cis-retinal
83
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
Providing substrate for glyceraldehyde-3-phosphate
| dehydrogenase
84
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
3 moles of ATP
85
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
Pancreatic glucokinase
86
```
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
```
–4.0 Kcal/mol
87
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
Low Km of hexokinase
88
In the reaction below, Nu TP stands for
NuTP + glucose → Glucose 6–Phosphate + NuDP.
(A) ATP (B) CTP
(C) GTP (D) UTP
ATP
89
```
In the glycolytic pathway, enolpyruvate is converted to ketopyruvate by
(A) Pyruvate kinase
(B) Phosphoenolpyruvate
(C) Pyruvate dehydrogenase
(D) Spontaneously
```
Spontaneously
90
```
In erythrocytes, 2, 3-biphosphoglycerate
is derived from the intermediate:
(A) Glyeraldehyde-3-phosphate
(B) 1, 3-Biphosphoglycerate
(C) 3-Phosphoglycerate
(D) 2-Phosphoglycerate
```
1, 3-Biphosphoglycerate
91
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
Displacement of the oxyhemoglobin
| dissociation curve to the right
92
```
Erythrocytes under normal conditions and
microorganisms under anaerobic conditions may accumulate
(A) NADPH
(B) Pyruvate
(C) Phosphoenolpyruvate
(D) Lactate
```
Lactate
93
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
Glyceraldehyde-3-phosphate dehydrogenase
94
Phosphofructokinase key enzyme in
glycolysis is inhibited by
(A) Citrate and ATP (B) AMP
(C) ADP (D) TMP
Citrate and ATP
95
```
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
```
Glucose-6-Phosphate
96
The net number of ATP formed per mole of glucose in anaerobic glycolysis is
(A) 1 (B) 2
(C) 6 (D) 8
2
97
```
Pyruvate dehydrogenase a multienzyme complex is required for the production of
(A) Acetyl-CoA
(B) Lactate
(C) Phosphoenolpyruvate
(D) Enolpyruvate
```
Acetyl-CoA
98
```
Dietary deficiency of thiamin inhibits the
activity of the enzyme:
(A) Pyruvate kinase
(B) Pyruvate dehydrogenase
(C) Phosphofructokinase
(D) Enolase
```
Pyruvate dehydrogenase
99
Pyruvate dehydrogenase activity is inhibited by
(A) Mercury (B) Zinc
(C) Calcium (D) Sodium
Mercury
100
All the enzymes of glycolysis pathway are found in
(A) Extramitochondrial soluble fraction of the cell
(B) Mitochondria
(C) Nucleus
(D) Endoplasmic reticulum
Extramitochondrial soluble fraction of the cell
101
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
Citric acid cycle
102
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
Mitochondrial matrix
103
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
Condensation of acetyl-CoA with oxaloacetate
104
The substance which may be considered to play a catalytic role in citric acid cycle is
(A) Oxaloacetate (B) Isocitrate
(C) Malate (D) Fumarate
Oxaloacetate
105
```
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
```
α-Ketoglutarate dehydrogenase
106
The reaction catalysed by α-ketoglutarate dehydrogenase in the citric acid cycle requires
(A) NAD (B) NADP
(C) ADP (D) ATP
NAD
107
```
In TCA cycle, oxalosuccinate is converted to α-ketoglutarate by the enzyme:
(A) Fumarase
(B) Isocitrate dehydrogenase
(C) Aconitase
(D) Succinase
```
Isocitrate dehydrogenase
108
The enzyme a-ketoglutarate dehydrogenase in the citric acid cycle requires
(A) Lipoate (B) Folate
(C) Pyridoxine (D) Inositol
Lipoate
109
The number of ATP molecules generated for each turn of the citric acid cycle is
(A) 8 (B) 12
(C) 24 (D) 38
12
110
Oxidation of one molecule of glucose yields
(A) 12 ATP (B) 24 ATP
(C) 38 ATP (D) 38 ATP
38 ATP
111
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
Lactate
112
Mitochondrial membrane is freely permeable to
(A) Pyruvate (B) Malate
(C) Oxaloacetate (D) Fumarate
Malate
113
The coenzyme not involved in the
formation of acetyl-CoA from pyruvate is
(A) TPP (B) Biotin
(C) NAD (D) FAD
Biotin
114
A carrier molecule in the citric acid cycle is
(A) Acetyl-CoA (B) Citrate
(C) Oxaloacetate (D) Malate
Oxaloacetate
115
```
The rate of citric acid cycle is controlled
by the allosteric enzyme:
(A) Aconitase
(B) Fumarase
(C) Fumarase
(D) Malate dehydrogenase
```
Fumarase
116
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
Phosphorylated-dephosphorylated-rephosphorylated
117
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
Glucose 6-phosphate → glucose 1-phosphate
118
```
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
```
Muscle
119
Allosteric activator of glycogen synthase is
(A) Glucose (B) Glucose-6-Phosphate
(C) UTP (D) Glucose-1-phosphate
Glucose-6-Phosphate
120
The hormone activating the glycogen
synthase activity is
(A) Insulin (B) Glucagon
(C) Epinephrine (D) ACTH
insulin
121
Action of glycogen synthase is inhibited by
(A) Insulin (B) Glucose
(C) Mg2+ (D) Cyclic AMP
Mg2+
122
```
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
```
Glucose-6-phosphate dehydrogenase
123
```
The sites for gluconeogenesis are
(A) Liver and kidney
(B) Skin and pancreas
(C) Lung and brain
(D) Intestine and lens of eye
```
Liver and kidney
124
```
An enzyme involved in gluconeogenesis is
(A) Pyruvate kinase
(B) Pyruvate carboxylase
(C) Hexokinase
(D) Phosphohexose isomerase
```
Pyruvate carboxylase
125
```
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
```
10
126
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
Ethanol’s carbons are lost as carbon dioxide before
| a gluconeogenic precursor can be generated
127
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
Malate to coenzyme Q
128
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
Dinitrophenol
129
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
22.5 moles of ATP per mole of citrate
130
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
Pyridoxal phosphate
131
```
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
```
Cytoplasmic malate dehydrogenase
132
```
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
```
Vitamin E
133
```
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
```
B12
134
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
Easy bruising
135
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
Formation of γ-carboxyglutamate
136
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
Methylmalonic acid
