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1

The minimum amount of energy required to bring about a chemical reaction is called:

 

Activation energy

2

Which of the following is not a property of enzymes?

A) Capable of being regulated

B) Reaction rates high in comparison to uncatalyzed  reaction

C) Highly specific

D) Side products of reactions are rare

E) All of the above are true

All of the above are true

3

Consider the following reaction diagram. Which letter indicates the transition state?

C

4

In contrast to inorganic catalysts, enzymes have an intricately shaped surface called the __________.

Active Site. Each active site  is a cleft or crevice in a large protein molecule into which substrate molecules can  bind in a catalysis-promoting orientation.

5

The lock and key model of enzyme activity proposes that each:

Enzyme binds a specific substrate because the active site and substrate have complementary structures.

6

The synthesis of enzymes in response to changing metabolic needs is referred to as:

 

Enzyme induction, allows cells to respond efficiently to changes in their enviorment.

7

Which of the following is a coenzyme?

NADP+ (complex organic molecule

8

Alcohol dehydrogenase without NAD+ is called a _______:

Apoenzyme (The protein component of an enzyme that lacks an essential cofactor)

9

The term synthetase is included in which class of enzymes?

Ligases

10

Which of the following is not a type of oxidoreductase?

A Peroxidase

B) Hydroxylase

C) Reductase

D) Dehydrogenase

E) Peptidase

Peptidase

11

Which of the following classes of enzymes catalyze reactions involving the cleavage of bonds by the addition of water?

Hydrolase

12

Consider the following reaction data.

Alanylanine + water -----à  alanine

[alanylanine}                                       [water]              Rate

0.1                                                       0.1                   1x 10-4

0.2                                                       0.1                   2x10-4

0.1                                                       0.2                   2x10-4

0.2                                                       0.2                   4x10-4

The reaction is _______ order overall.

Second

13

The steady state assumption states that if:

K1 = the rate constant for ES formation

K2 = the rate constant for ES dissociation

K3 = the rate constant for product formation

 

The rate of formation of ES is equal to the rate of its degradation over the course of the reaction

 

14

The expression of the Michaelis constant is equal to:

Where

K1 = the rate constant for ES formation

K2 = the rate constant for ES dissociation

K3 = the rate constant for product formation

 km=(K2 + K3)/K1

15

Specific activity is defined as

The number of I.U. per mg of protein (quantity used to measure enzyme purification)

16

In the Lineweaver-Burk double reciprocal plot the slope is equal to _____.

Km/Vmax

17

In the Lineweaver-Burke double reciprocal plot the vertical intercept is equal to ____.

1/Vmax

 

18

In the Lineweaver-Burke double reciprocal plot the horizontal intercept is equal to _________.

–1/Km

19

In competitive inhibition, increasing the concentration of substrate:

Increases the overall rate of the reaction

20

Which of the following amino acids is capable of acting as a general acid or general base at physiological pH ?

Histidine

21

Which of the following amino acids can participate in covalent catalysis?

A) Tryptophan

B) Tyrosine

C) Serine

D) Histidine

E) Both C and D are correct

Serine & Histidine

22

Which of the following is a feature of transition metals that makes them efficient cofactors?

A) Have a high concentration of positive charge

B) Can act as a Lewis acid

C) Have directed valences

D) Can exist as a variety of valence states

E) All of the above are correct

All of the above are correct.

23

NADPH and NADH are coenzymes found in which class of enzymes?

 

Dehydrogenases

24

Which of the following is not present in the active site of alcohol dehydrogenase?

A) Zn++

B) Histidine

C) Cysteine

D) NAD+

E) Proline

Proline

25

Enzyme control is accomplished in which of the following ways?

A) Genetic control

B) Covalent modification

C) Allosteric regulation

D) Compartamentation

E) All of the above are correct

All of the above are correct

26

Zymogens are a feature of what type of enzymatic control?

Covalent modification

27

 Regulatory enzymes are a feature of what type of enzymatic control?

Covalent modification & Allosteric regulation

28

Positive cooperativity is a feature of what type of enzymatic control?

Allosteric regulation

29

Segregation of biochemical pathways into different organelles in an example of which type of enzymatic regulation?

Compartmentation

30

Catalysts are effective because they:

Decrease the activation energy of a reaction

31

 Enzymes act by _________.

 Decreasing the energy of activation of a reaction & Providing a surface to favorably orient the reactants

32

Enzyme studies are best carried out:

 

In the presence of an inert crowding agent

33

Alcohol dehydrogenase is an example of which of the following classes of enzymes?

Oxidoreductases

34

Which of the following is not an assumption of the law of mass action?

A) Forward reaction is linear

B)  Reverse reaction is linear

C) System is homogenous

D)  Interacting molecules move randomly and independently of each other

E) All are assumptions of the law of mass action

All are assumptions of the law of mass action

35

Metabolons are defined as:

Complexes that channel product molecules  from one active site to another

36

Metabolic flux is best defined as a:

Rate of flow of metabolites from one point to another in a pathway

37

Which of the following molecules can most easily facilitate quantum mechanical tunneling? 

A) NADH

B) NADD

C) NADT

D) All of the above are correct

E) None of these molecules are involved in tunneling

NADH

38

Which of the following amino acids cannot actively participate in a catalytic site?

A) Serine

B) Threonine

C) Tyrosine

D) Lysine

E) Glutamine

Lysine

39

In addition to serine and aspartate which of the following amino acids is a member of the serine triad?

Histidine

40

Which of the following is not an important metal in biological systems

A) Na+

B) K+

C) Mg++

D) Cu++

E) Ba++

Ba++

41

Both glycogenesis and glycogenolysis are controlled primarily by the interplay between the two hormones insulin and ________.

Glucagon

42

Hexokinase D is found in the _______.

 

Liver

43

An enzyme family called the _________ catalyzes the phosphorylation of hexoses in the body.

Hexokinases

44

The conversion of glucose-1-phosphate to UDP-glucose has a DG0’ near zero. Which of the following reactions is coupled with the above reaction to drive it to completion?

 

Hydrolysis of PPi

45

Which of the following is required for the conversion of UDP-glucose to glycogen?

A) Glycogen synthase

B) Branching enzyme

C) Glucose phosphorlyase

D) Debranching enzyme

E) Both A and B are correct

Both A and B are correct

46

A glycogen molecule that has been degraded to its branch points is called

Limit dextrin

47

Regulation of glycolysis involves all of the following except

A) Insulin

B) Glucagon

C) SREBP1c

D) AMPK

E) None of the above

???

48

The binding of insulin to receptors on the surface of muscle cells stimulates which of the following processes

Glycogenesis

49

Under stressful conditions epinephrine is released from the adrenal medulla. The release of epinephrine has which of the following effects on glucose metabolism?

 

A) Glycogenolysis is stimulated

B) Glycogenesis is inhibited

C) Adenylate cyclase is activated

D) Both A and B are correct

E) All of the above are correct

All of the above are correct

50

Phosphorylase kinase

Converts inactive phosphorylase  to active phosphorylase

51

Cori’s disease is caused by

A deficiency of debranching enzyme

52

Which of the following activates phosphoprotein phosphatase?

Insulin

53

Glucose-6-phosphate is a substrate in which of the following processes

 

A) Gluconeogenesis

B) Glycolysis

C) Photosynthesis

D) Glycogenolysis

E) Both A and B are correct

Both A and B are correct

54

Fructose-2,6-biphosphate

Is an indicator of high cellular glucose concentration

55

The Embden-Myerhof pathway is also referred to as

Glycolysis

56

In glycolysis ________ moles of ATP are produced per mole of glucose consumed.

2

57

In glycolysis ________ moles of NADH are produced per mole of glucose consumed

2

58

The presence of which of the following molecules indicates that the cell has sufficient energy reserves?

A) ATP

B) Citrate

C) ADP

D) Fructose-1,6-biphosphate

E) Both A and B are correct

Both A and B are correct

59

Which of the following enzymes is an oxidoreductase?

Glyceraldehyde-3-phosphate dehdyrogenase

60

The first reaction in the oxidative phase of the pentose phosphate pathway is catalyzed by

Glucose-6-phosphate dehydrogenase

61

Which of the following enzymes catalyzes an irreversible process

Pyruvate kinase

62

In anaerobic organisms pyruvate is used to regenerate cellular ________

NAD+

63

Allosteric regulation of which of the following enzymes is important in the regulation of glycolysis?

A) Hexokinase

B) PFK-1

C) Pyruvate kinase

D) Both A and C are correct

E) All of the above are correct

All of the above are correct

64

Gluconeogenesis occurs primarily in the

Liver

65

) Which of the following molecules can be used to synthesize glucose via gluconeogenesis.

 

A)  Lactate

B) Pyruvate

C) Glycerol

D) Keto acids

E) All of the above are correct

All of the above are correct

66

Which of the following is the most important glucogenic amino acid?

 

A) Aspartate

B) Alanine

C) Glycine

D) Glutamate

E) All are equally important

Alanine

67

Gluconeogenesis is stimulated by high concentrations of which of the following compounds?

A) Lactate

B) Glycerol

C) Amino acid

D) Both A and B are correct

E) All of the above are correct

All of the above are correct

68

Which of the following is an oxidizing agent in fermentation?

A) Lactate

B) Glucose

C) NADH

D) Pyruvate

E) ADP

 

Pyruvate

69

In addition to glucose which of the following sugars are important in the human diet?

A) Fructose

B) Galactose

C) Mannose

D) Sucrose

E) Both A and D are correct

Sucrose

70

Intermediates in the nonoxidative phase of the pentose phosphate pathway include all of the following except

 

A) Dihydroxyacetone phosphate

B) Sedoheptulose-7-phosphate

C) Fructose-6-phosphate

D) Xylulose-5-phosphate

E) Erythrose-4-phosphate

Dihydroxyacetone phosphate

71

The use of a highly exergonic reaction in the beginning of a catabolic pathway is referred to as 

Turbo design

72

Aldol cleavage of which of the following sugars will produce one mole each of dihydroxyacetone and glyceraldehyde?

Fructose

73

Which of the following is a second messenger in glycogenolysis?

A) Glucagon

B)  Insulin

C)  Glucose

D)  ATP

E) cAMP

 

cAMP

74

Phosphoroylation of glucose upon entering the cell has what effect?

Prevents the glucose from leaving again and Activates the glucose for further reaction

75

Physiologically, the most important kinases are  glycogen kinase and  ________

 

Casein kinase

76

Which of the following enzymes is not required in gluconeogenesis?

 

A) Phosphoenolpyruvate carboxekinase

B)  Phosphofructokinase

C)  Pyruvate kinase

D) Fructose-1,6-bisphosphatase

E)  Pyruvate carboxylase

Phosphofructokinase

77

The final product of glycolysis is

 

Pyruvate

78

The principal products of the pentose phosphate pathway include

NADPH and Ribose-5-phosphate

79

Flux of which of the following sugars into the glycolytic pathway is essentially unregulated.

A) Glucose

B) Fructose

C) Glucose-1-phosphate

D) Both A and C are correct

E) None of the above are correct

Fructose

80

Conversion of fructose-6-phosphate to fructose-1,6-bisphosphate has two purposes. One is the commitment of the molecule to glycolysis, the second is

 

Preventing the cleavage products of the next step from diffusing out of the cell

81

Enzymes act by _________.

Decreasing the energy of activation of a reaction and Providing a surface to favorably orient the reactants

82

In the graph reaction rate vs substrate concentration, the reason that the curve reaches a plateau, and does not increase any further at high substrate concentration is that:

. the active site is saturated with substrate

83

Regulatory enzymes are a feature of what type of enzymatic control?

Allosteric regulation

84

Zymogens are a feature of what type of enzymatic control?

Covalent modification

85

Enzyme control is accomplished in which of the following ways?

Genetic control; Covalent modification; Allosteric regulation; Compartamentation

86

NADPH and NADH are coenzymes found in which class of enzymes?

Dehydrogenases

87

Which of the following amino acids can participate in covalent catalysis?

A) Tryptophan;  B) Tyrosine;  C) Serine;  D) Histidine;  E) Both C and D are correct

Serine and Histidine

88

Which of the following is the abbreviated formula of the tetrapeptide shown below? (Hint: remember to start at the N-terminal end.)

 

asp-ala-ser-lys

89

Which of the following classes of enzymes catalyze reactions involving the cleavage of bonds by the addition of water?

 

Hydrolase

90

The expression of the Michaelis constant is equal to:

(K2 + K3)/K1

91

The lock and key model of enzyme activity proposes that each:

Enzyme binds a specific substrate because the active site and substrate have complementary structures

92

Which of the following structures is the beta-anomer of D-glucose:

93

The structures below can be identified as:

1=aldose, 2=ketose

94

The figure below shows which type of chemical reaction:

mutarotation in solution

95

The figure below shows a redox reaction used to identify glucose.  In this reaction:

Glucose is oxidized to an aldonic acid

96

Which one of the following is not true concerning D-glucose? 

A.     D-glucose is a reducing sugar; 

B.     D-glucose readily forms cyclic hemiacetals.; 

C.    D-glucose is optically active;      

 D.   D-glucose is a ketose.

D-glucose is a ketose.

97

The alpha and beta forms of D-glucopyranose can be described as  

 

anomers.

98

The first step in glycolysis is phosphorylation of glucose to form glucose-6-phosphate. This action serves to:

Make glucose more polar, locking it within the cell

99

The end product of glycolysis under anaerobic conditions is:

 Lactic acid

100

Which of the following decreases the rate of glycolysis in a tissue?

Citric acid

101

An enzyme family called the _________ catalyzes the phosphorylation of hexoses in the body.

Hexokinases

102

Under stressful conditions epinephrine is released from the adrenal medulla. The release of epinephrine has which of the following effects on glucose metabolism?

A) Glycogenolysis is stimulated; 

B) Glycogenesis is inhibited; 

C) Adenylate cyclase is activated

D) Both A and B are correct; 

E) All of the above are correct

All of the above are correct

103

One of the early steps in glycogenesis is formation of UDP-glucose from glucose-1-phosphate and UTP according to the reaction:

Glucose-1-phosphate + UTP → UDP-glucose + PPi

One would expect this reaction to occur spontaneously if ΔG° were large and negative, but in fact, ΔG° for this reaction is nearly zero. What, then, drives the reaction?

Presence of the ubiquitous enzyme pyrophosphatase, which rapidly hydrolyzes pyrophosphate

104

We consume some fructose in our diet. The fructose can provide energy by:

Phosphorylation by fructokinase or hexokinase to form fructose-1-phosphate or fructose-6-phosphate and further oxidation through glycolysis

 

105

The principal products of the pentose phosphate pathway include

NADPH & Ribose-5-phosphate

106

During metabolism in a certain tissue, glucose is oxidized, ATP is generated, and NAD + is reduced to NADH. At the same time, CO 2 is released. The most likely type of metabolism here is:

Alcoholic fermentation

107

Gluconeogenesis is stimulated by high concentrations of which of the following compounds?

A) Lactate; 

B) Glycerol; 

C) Amino acid; 

D) Both A and B are correct;

E) All of the above are correct

All of the above are correct

108

Allosteric regulation of which of the following enzymes is important in the regulation of glycolysis?

A) Hexokinase;   

B) PFK-1; 

C) Pyruvate kinase; 

D) Both A and C are correct; 

E) All of the above are correct

All of the above are correct

109

The presence of which of the following molecules indicates that the cell has sufficient energy reserves?

A) ATP; 

B) Citrate; 

C) ADP; 

D) Fructose-1,6-biphosphate; 

E) Both A and B are correct

Both A and B are correct

110

The end product of glycolysis under anaerobic conditions is:

Lactic acid

111

 Phosphofructokinase is allosterically inhibited by high concentrations of

 

ATP

112

The process by which ATP is formed from ADP in glycolysis is referred to as

substrate-level phosphorylation

113

In glycolysis ________ moles of ATP are produced per mole of glucose consumed.

2

114

Which of the following molecules can be used to synthesize glucose via gluconeogenesis.

A)  Lactate; 

B) Pyruvate; 

C) Glycerol; 

D) Keto acids; 

E) All of the above are correct

All of the above are correct

115

Which of the following is the most important glucogenic amino acid?

Alanine

116

In the figure below the glucose-alanine cycle is shown.  In this cycle the alanine is derived in the muscle from the …..…….amino acid  by a …………reaction.

Pyruvate/ transamination;

117

In the degradative pathway major nutrients are _________ broken down, resulting in the synthesis of __________ .

exergonically; ATP

118

Conversion of galactose to glucose is accomplished by a(n)

Epimerase

119

Which of the following statements about glycogen is false?

A) Glycogen is a polymer of glucose in (14) linkages with (16) linked branches every 8–14 residues.

B) Glycogen is the storage polysaccharide in skeletal muscle and liver cells.
C) UDP–glucose is produced from glycogen by the action of the enzyme phosphorylase.
D) In glycogen breakdown, glucose residues are sequentially removed from the nonreducing ends.

UDP–glucose is produced from glycogen by the action of the enzyme phosphorylase.

120

In which cellular location does the following reaction take place?

pyruvate + HCO3- + ATP  ® oxaloacetate + ADP + Pi

mitochondrial matrix

121

In glycolysis ________ moles of NADH are produced per mole of glucose consumed

2

122

In the figure below identify the enzymes catalyzing the specific reactions:

1- glyceraldehyde 3-phosphate dehydrogenase; 2-pyruvate kinase

123

What are the coenzyme forms that correspond to X and Y in the following gluconeogenic reaction catalyzed by glyceraldehyde-3-phosphate dehydrogenase?

X = NADH + H+ ,Y = NAD+

124

Acyl phosphates such as 1,3-bisphosphoglycerate have a ______ phosphoryl group transfer potential compared to ATP, which can be recognized by the _______ deltaG°' values for hydrolysis.

greater; more negative

125

The ubiquitous chemistry of acetyl-CoA is centered on its high-energy _________________ bond.

phosphothioester

126

Which of the following is (are) associated with cAMP binding to cAMP-dependent protein kinase A?

A)cAMP binds to the regulatory subunits

B) regulatory subunits dissociate from catalytic subunits

C) catalytic subunits phosphorylate multiple targets with specifc serines and threonines

D) A and B

E) A, B, and C

A, B, and C

127

In liver cells, if cAMP concentrations are high

PFK-2/FBPase-2 will function to degrade F-2,6-P, thereby enhancing gluconeogenesis & depressing glycolysis.

128

Which of the following enzymes converts phosphorylase b is to the more active phosphorylase a?

A)cAMP-dependent protein kinase;  

B) phosphorylase kinase

C)glycogenin; 

D)calmodulin

E) phosphoprotein phosphatase-1

phosphorylase kinase

129

Which of the following serves as the free energy sourcefor the metabolic conversion of oxaloacetate to phosphoenolpyruvate, which is catalyzed by PEP carboxykinase?

A) hydrolysis of ATP —> ADP + Pi; 

B) hydrolysis of ATP —> AMP + PPi —> 2Pi

C)hydrolysis of GTP —> GDP + Pi;

D)hydrolysis of an internal phosphoanhydride

hydrolysis of GTP —> GDP + Pi;

130

Muscle cells are not able to supply glucose for other tissues because they do not contain which of the following enzymes?

A) debranching enzyme; B) pyruvate carboxylase; C) glucose-6-phosphatase
phosphoglucomutase;  E) glycogen phosphorylase

glucose-6-phosphatase

131

The reaction below is catalyzed by:

Glycogen synthase

132

Which of the following best describes the citric acid cycle as a central pathway of metabolism?

A) It is important for recovery of energy from carbohydrates only.
B) It is important for recovery of energy from fatty acids only.
C) It is important for recovery of energy from amino acids only.
D) It is important for recovery of energy from several metabolic fuels that are broken down to acetyl-CoA.
E) Only A) and B) above

It is important for recovery of energy from several metabolic fuels that are broken down to acetyl-CoA.

133

The reduced coenzymes of the TCA cycle, such as FADH 2 and NADH, must pass their electrons into the electron transport chain to produce ATP, but one step of the TCA cycle yields a compound with high transfer potential that can provide energy for phosphorylation of ADP at the substrate level. What is this high-energy compound?

Succinyl CoA

134

You may have learned the term B amphoteric B used in general chemistry to describe a substance that could function as either an acid or a base. When we describe the TCA cycle as amphibolic, we mean that it:

Is capable of both synthetic and degradative reactions

135

In addition to the regulators of enzyme activity within the citric acid cycle, two enzymes outside the cycle profoundly affect its activity. Which ones?

Pyruvate carboxylase and pyruvate dehydrogenase

136

Which of the following citric acid cycle intermediates can be converted to aspartate via transamination?

A)Citrate; 

B)alpha-ketoglutarate;

C)succinate;

D) fumarate;

E)oxaloacetate

oxaloacetate

137

Which of the following conversions is an anaplerotic reaction of the citric acid cycle?

A) Pyruvate to oxaloacetate;

B) Ceretain amino acids to succinyl CoA;

C) Glutamate to alpha-ketoglutarate;

D) Aspartate to oxaloacetate;

E) All of the above are correct

All of the above are correct

138

NADH and NADPH are major coenzymes for oxidoreductases. While nearly equivalent in redox potential, the two coenzymes often function in different metabolic actions. In general:

NADH is often involved in degradation and NADPH in synthesis

139

Formation of ATP is increased by

A high ratio of ADP to ATP

140

If not otherwise dangerous, uncouplers would make good diet aids because:

They allow protons to pass through the mitochondrial membrane without ATP synthesis

141

Formation of ATP as a result of passage of electrons through the ETC is sometimes called oxidative phosphorylation because:

As substrates are oxidized, ADP is phosphorylated to form ATP

142

Among the important antioxidant molecules taken in with our food are:

α-Tocopherol, β-carotene, and ascorbic acid

143

Mitchell's chemiosmotic theory suggested that a high concentration of protons outside the mitochondrial membrane:

Generated a voltage and a protonmotive force which helped drive the ATP synthase

144

Branched-chain fatty acids, such as phytanic acid, are not a lost cause as sources of energy. They may be broken down by a process with begins with:

α-oxidation

145

The location of fatty acid oxidation is:

The mitochondrial matrix

146

Drugs called statins are now used to decrease plasma cholesterol levels by inhibiting the rate-limiting step of cholesterol synthesis. This step is catalyzed by:

HMG-CoA reductase

147

Fatty acid oxidation occurs mostly within mitochondria, but fatty acids themselves canB t easily cross the mitochondrial membrane. How do they pass?

As esters of carnitine

148

Fatty acid synthesis is dependent upon aggregation of dimers of acetyl-Co carboxylase to form polymers. This aggregation is slowed or prevented by:

Glucagon

149

Which of the following statements about the transport of fatty acyl-CoA derivatives (activated fatty acids) into the mitochondria is correct?

Only the acyl groups of fatty acyl-CoA derivatives are attached to carnitine.

150

The dietary fats are transported as

Chylomicons

151

Which statement best describes the oxidation of odd chain fatty acids?

a)   Additional specific enzymes are needed for the oxidative process

b)   One carbon is removed in one cycle

c)   End product is propionyl co A

d)   Hydroxy fatty acids are produced

End product is propionyl co A

152

The key regulatory enzyme of fatty acid synthesis is-

Acetyl co A carboxylase

153

Malonyl co A is a direct inhibitor of which enzyme of fatty acid oxidation?

Carnitine Acyl Transferase –I

154

Which out of the followings is the primary ketone body?

a)   Acetone

b)   Acetoacetate

c)   Beta-hydroxy butyrate

d)   Hydroxy Methyl glutarate

Acetoacetate

155

The key regulatory enzyme of cholesterol synthesis is-

HMG Co A reductase

156

Which of the following statements about triacylglycerols is correct?

Triacylglycerols are hydrolysed to glycerol and fatty acids.

157

Which of the following statements about the activation of fatty acids is correct?

Fatty acid activation requires energy in the form of ATP.

158

Which of the following statements about the transport of fatty acyl-CoA derivatives (activated fatty acids) into the mitochondria is correct?

a) Only the acyl groups of fatty acyl-CoA derivatives are attached to carnitine.

b) Fatty acyl-CoA derivatives can diffuse into the mitochondrial matrix because they are hydrophobic.

c) Fatty acyl-CoAs are carried into the mitochondrial matrix by a carnitine shuttle.

d) Fatty acyl-CoAs are oxidised in the mitochondrial matrix because most of the ATP generated is needed there.

Only the acyl groups of fatty acyl-CoA derivatives are attached to carnitine.

159

The ETC component that transfers electrons directly to oxygen is __________.

Cytochrome oxidase

160

During the oxidation of NADH there are several steps in which  deltaEo’  is sufficient for ATP synthesis. These occur within

Complexes I, III and IV

161

ATP synthesis and mitochondrial electron transport are coupled by

Protonmotive force & Proton gradient

162

In Complex I of the ETC, the major sources of NADH include

Fatty acid oxidation &  The citric acid cycle

163

In Complex III, electrons are tranferred from UQH2 to

Cytochrome

164

The final product of oxidative phosphorylation is ________.

ATP

165

The return of ______ into the mitochondrion is coupled to the formation of ______.

H+/ATP

166

The energy that is captured by the electron transport system is in the form of

NADH & FADH2

167

The cytochromes contain which type of prosthetic group?

Heme

168

The function of complex III is the transfer of electrons from

Coenzyme Q to Cyt c

169

How many ATP are generated during the oxidation of one NADH?

2.5

170

How many ATP are generated during the oxidation of one FADH2?

1.5

171

Which of the following are true statements about the structure of ATP synthase?

A)It has a membrane-embedded component called F0 and a component found in the matrix referred to as F1;

B) The g subunit acts as a “cam” shaft in the rotational motor; 

C) The structure has a “lollipop” shape

D) A and B;

E)A, B, and C

A, B, and C

172

Which of the following energy sources drives the phosphate carrier that transports Pi into the mitochondria from the cytosol?

A)ATP hydrolysis

B)simultaneous transport of H+ into the mitochondrion;  C)simultaneous transport of ADP into the mitochondrion;  D)simultaneous transport of H+ out of the mitochondrion;  E)simultaneous transport of ATP out of the mitochondrion

simultaneous transport of H+ into the mitochondrion

173

Which of the following statements are true about oxidative phosphorylation?

A)Electron transport provides energy to pump protons into the intermembrane space.

B)An electrochemical gradient is formed across the inner mitochondrial membrane.

C) Potassium and sodium ions form an ionic gradient across the inner mitochondrial membrane.

D) A and B; 

E) A, B, and C

A and B

174

Recognize the structures below and choose the best answer for the indicated labels:

1= coenzyme Q; 2= 1e- ; 3= coenzyme Q.- ; 4= e- + 2H+; 5= coenzymeQH2

175

The overall reaction catalyzed by pyruvate dehydrogenase is which of the following?

A) CH3COCHO  + NAD+ + CoASH →CH3CHOSCoA + NADH

B) CH3COCOO- + FAD +CoASH →CH3CHSCoA  + NADH

C) CH3COCOO- + NAD+ + CoASH →CH3COSCoA + NADH

D) CH3CH(OH)COO- + NADH + CoASH → CH3CH(OH)COSCoA + NAD+

CH3COCOO- + NAD+ + CoASH →CH3COSCoA + NADH

176

Which statement concerning Complex II of the electron transport chain is false?

A) This complex oxidizes FADH2 and reduces coenzyme Q.;

B) This complex includes a cytochrome heme.; 

C)This complex includes Fe-S centers;

D) This complex pumps protons from the matrix to the intermembrane space;

E)This complex also oxidizes succinate to fumarate in the TCA cycle.

This complex includes a cytochrome heme.

177

Which is the enzyme catalyzing the two steps reaction below and which is the metabolic pathway in which this reaction occurs?!

Acetyl-CoA carboxylase, fatty acids synthesis

178

Some chemical reactions catalyzed by the multifunctional fatty acid synthase are shown below.Identify the enzymes that catalyze each of the indicated steps:

4 beta-Ketoacyl-ACP Reductase; 5 beta-Hydroxyacyl-ACP Dehydratase; 6 Enoyl-ACP Reductase

179

During starvation, DHAP used to synthesize triacylglycerols is provided by a simplified version of gluconeogenesis called

Ketosis

180

Cholesterol is a precursor to:

steroid hormones such as androgens

181

The _____ are synthesized from C20 fatty acids such as ______ and trigger pain and inflammation.

prostaglandins, arachidonate

182

Which of the following citric acid cycle intermediates can be converted to aspartate via transamination?

oxaloacetate

183

Place the following reaction intermediates of the citric acid cycle in chronological order. i. malate,  ii fumarate, iii succinylCoA, iv citrate, v α-ketoglutarate.

Citrate, α-ketoglutarate, succinyCoA, Fumarate, malate 

184

FADH2 is a product of which of the following reactions?

Succinate → Fumarate

185

Acetyl CoA that is consumed by the citric acid cycle is produced from which of the following biochemical pathways?

Glycolysis; Fatty acid Oxidation

186

The carbon skeletons of which of the following are direct precursors of amino acids? 

a-Ketoglutarate; Oxaloacetate

187

The overall reaction catalyzed by pyruvate dehydrogenase is which of the following?

CH3COCOO- + NAD+ + CoASH à CH3COSCoA + NADH

188

The citric acid cycle is a component of aerobic respiration. Molecular oxygen

Is only indirectly involved in the reactions of the cycle

189

The main toxic effect of oxygen is due to which of the following?

ROS

190

The first molecule of carbon dioxide is released from which of the following compounds in the citric acid cycle?

Isocitrate

191

The high energy molecule produced in the conversion of succinyl-CoA to succinate is which of the following

ATP; GTP

192

Which of the following conversions is an anaplerotic reaction of the citric acid cycle?

A) Pyruvate to oxaloacetate

B) Ceretain amino acids to succinyl CoA

C) Glutamate to a-ketoglutarate

D) Aspartate to oxaloacetate

E) All of the above are correct

 

 

 

All of the above are correct

193