Exam 2 Flashcards

(193 cards)

1
Q

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

A

Activation energy

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2
Q

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

A

All of the above are true

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3
Q

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

A

C

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4
Q

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

A

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.

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5
Q

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

A

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

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6
Q

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

A

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

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7
Q

Which of the following is a coenzyme?

A

NADP+ (complex organic molecule

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8
Q

Alcohol dehydrogenase without NAD+ is called a _______:

A

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

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9
Q

The term synthetase is included in which class of enzymes?

A

Ligases

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10
Q

Which of the following is not a type of oxidoreductase?

A Peroxidase

B) Hydroxylase

C) Reductase

D) Dehydrogenase

E) Peptidase

A

Peptidase

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11
Q

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

A

Hydrolase

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12
Q

Consider the following reaction data.

Alanylanine + water —–à alanine

[alanylanine} [water] Rate

  1. 1 0.1 1x 10-4
  2. 2 0.1 2x10-4
  3. 1 0.2 2x10-4
  4. 2 0.2 4x10-4

The reaction is _______ order overall.

A

Second

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13
Q

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

A

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

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14
Q

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

A

km=(K2 + K3)/K1

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15
Q

Specific activity is defined as

A

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

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16
Q

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

A

Km/Vmax

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17
Q

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

A

1/Vmax

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18
Q

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

A

–1/Km

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19
Q

In competitive inhibition, increasing the concentration of substrate:

A

Increases the overall rate of the reaction

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20
Q

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

A

Histidine

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21
Q

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

A

Serine & Histidine

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22
Q

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

A

All of the above are correct.

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23
Q

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

A

Dehydrogenases

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24
Q

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

A) Zn++

B) Histidine

C) Cysteine

D) NAD+

E) Proline

A

Proline

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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? ## Footnote 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 ## Footnote 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? ## Footnote 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 ## Footnote 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? ## Footnote 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? ## Footnote 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? ## Footnote 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? ## Footnote 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? ## Footnote 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? ## Footnote 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? ## Footnote 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? ## Footnote 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? ## Footnote 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? ## Footnote 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