EXAM 3 Flashcards

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1
Q

The reaction pathway that transforms fuels into cellular energy

A

Catabolic

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2
Q

The metabolic pathways the require energy and are often biosynthetic processes

A

Anabolic

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3
Q

Which energy source is used to regenerate ATP from ADP and Pi

A

oxidation of carbon to CO2

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4
Q

What are the major purposes for which organisms require energy

A
  • the performance of mechanical work
  • active transport
  • the synthesis of biomolecules
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5
Q

What is the standard-state free energy for the hydrolysis of ATP to ADP

A

-30kJ/mol

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6
Q

Electron donor used for reductive biosynthesis

A

NADPH

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7
Q

Activated carriers that contain adenosine phosphate groups

A
  • NADH
  • FADH2
  • coenzyme A
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8
Q

Metabolic processes are regulated by

A
  • Transcriptional regulation of the amount of enzyme
  • allosteric control of enzyme activity
  • the accessibility of substrates by compartmentalization
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9
Q

Organisms that use energy from sunlight and convert to chemical energy

A

Phototrophs

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10
Q

Organisms that obtain chemical energy from the oxidation of foodstuffs

A

Chemotrophs

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11
Q

Pathways can be either anabolic or catabolic, depending on the energy conditions of the cell

A

Amphibolic

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12
Q

In aerobic organisms, the ultimate acceptor of electrons is

A

Oxygen

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13
Q

In aerobic metabolism, the product of oxidation of carbon containing fuels is

A

Carbon Dioxide

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14
Q

The electron carrier, NADH, is derived from the _______ vitamin

A

Niacin

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15
Q

The chemical currency of metabolism

A

ATP

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16
Q

FAD is an electron carrier that is derived from the vitamin

A

Riboflavin (B2)

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17
Q

NADH and NADPH

A

niacin

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18
Q

FADH2

A

riboflavin

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19
Q

acetyl CoA

A

pantothenate

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20
Q

Biotin

A

biotin

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21
Q

Tetrahydrofolate

A

folate

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22
Q

The principle carbohydrate in living systems

A

Glucose

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23
Q

The product of aerobic glycolysis

A

2 pyruvate

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24
Q

The substance _______ must be regenerated for glycolysis to proceed in either aerobic or aerobic conditions

A

NAD+

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25
Q

An allosteric activator of glycolysis is

A

AMP

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26
Q

Glycolysis produces a net of ____ moles of ATP

A

2

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27
Q

The key regulatory enzyme for glycolysis is

A

PFK

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28
Q

________ are enzymes that catalyze the transfer of phosphoryl group from ATP to an acceptor

A

Kinases

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29
Q

In alcoholic fermentation, the decarboxylation of pyruvate requires a coenzyme that contains the vitamin_____

A

Thiamine (B1)

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30
Q

A potent allosteric activator of liver PFK if ________, which is produced from fructose-6–phosphate by PFK2

A

F 2,6-biphosphate

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31
Q

_________ mediate the thermodynamically downhill movement of glucose across plasma membranes

A

Glucose transporters

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32
Q

How is glycolysis maintained under anaerobic conditions?

A

Pyruvate can be reduced to either lactate or ethanol; this reaction is accompanied by the oxidation of NADH to regenerate NAD+

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33
Q

Which of the following is a reason that glucose is a common metabolic fuel used by living organisms?

Answers:	
A. 
It has a stable ring structure and is unlikely to glycosylate proteins.
B. 
It has been found as one of the monosaccharides formed under prebiotic conditions.
C. 
It is the only sugar used by the brain.
D. 
A and B
A

A and B

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34
Q
What is the purpose of phosphorylating glucose in cytosol?
A. 
to trap glucose in the cell
B. 
to destabilize glucose and facilitate the next series of metabolic steps
C. 
to convert it to a more soluble form
 D. 
A and B
A

A and B

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35
Q

What reaction is catalyzed by aldolase

A

reversible cleavage of F-1,6-BP to DHAP and GAP

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36
Q

What is the function of a thirster intermediate such as the one formed from GAP

A

The thirster allows the two-step reaction to be coupled so that the second reaction, the energetically unfavorable phosphorylation, can proceed

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37
Q

What is substrate-level phosphorylation?

A

ATP synthesis when the phosphate donor is a substrate with high-phosphoryl-transfer potential

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38
Q

What type of enzyme catalyzes the intramolecular shift of a chemical group?

A

Mutase

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39
Q
What are the primary metabolic fates of pyruvate?
A. 
ethanol
B. 
lactate
C. 
acetyl CoA
 D.
All of the above.
A

All of the above

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40
Q

Lactose intolerance is caused by a deficiency of

A

Lactase

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41
Q

Fructose from table sugar or high-fructose corn syrup and galactose form milk sugar converted to

A

glycolytic intermediates

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42
Q

During exercise, glycolysis is stimulated by a

A

feed-forward stimulation of pyruvate kinase

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43
Q

The process by which non carb precursor molecules are converted into glucose

A

Gluconeogensis

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44
Q

The stores of glucose are enough to support metabolism of a person for

A

1 day

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45
Q

The major tissue in which gluconeogenesis takes place is in the

A

liver

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46
Q

The conversion of glucose 6-phosphate to glucose takes place in the

A

lumen of the ER

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47
Q

The reaction that uses GTP and not ATP as its high-phosphoryl transfer donor is

A

PEP carboxylase

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48
Q

The compound__________ activates glycolysis and inhibits gluconeogenesis via conversion of fructose 1,6-bisphophate

A

F-2,6-BP

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49
Q

controls the synthesis and degradation of F-2,6-BP

A

PFK2

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50
Q

An intermediate that is decarboxylated and phosphorated to produce phophoenopyruvate

A

oxaloacetate

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51
Q

This essential nutrient is required for the carboxylation of pyruvate in human

A

Biotin

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52
Q

The ______ cycle is responsible for converting muscle lactate into glucose in the liver

A

Cori

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53
Q

Glycerol from fats is modified first by glycerol kinase and then a second enzyme to enter gluconeogensis at the intermediate

A

DHAP

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54
Q

How does the liver restore the level of glucose for active muscles

A

By converting lactate to glucose through the cori cycle

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55
Q

Biotin is a _____ for the pyruvate carboxylase reaction

A

cofactor

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56
Q

The phosphoryl donor in the formation of phosphoenolpyruvate is

A

GTP

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57
Q

The phosphorylation of glucose 6-phosphate takes place in which cellular location

A

The ER lumen

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58
Q
High levels of ATP and citrate: 
Answers:	
A.
indicate a high-energy–well-fed state.
B. 
promote gluconeogenesis.
C. 
inhibits glycolysis
D. 
All of the above
A

All of the above

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59
Q

What is an inhibitor of PFK?

A

citrate

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60
Q

The major site of gluconeogenesis is in which tissue?

A

Liver

61
Q

High blood sugar after a meal_______ the level of insulin released by the pancreas

A

Increases

62
Q

Insulin resistance is a hallmark of

A

type 2 diabetes

63
Q

Lactate produced in muscle tissue is converted to _____ by ______

A

glucose by the cori cycle

64
Q

How many high energy-phosphate bonds are expended to make one glucose in gluconeogensis

A

Six

65
Q

The citric acid cycle is also know as the

A

Krebs cycle & Tricarboxylic acid cycle

66
Q

Acetyl CoA is

A

The activated form of acyl groups

Fuel for the citric acid cycle

67
Q

Which enzyme(s) is/are responsible for the following reaction

Pyruvate + CoA + NAD+ —> Acetyl CoA + NADH + H+ + CO2

A

pyruvate dehydrogenase complex

68
Q

What are the steps involved in the conversion of pyruvate to acetyl CoA

A
  1. decarboxylation
  2. oxidation
  3. transfer to CoA
69
Q

Pyruvate dehydrogenase is _______ when ATP-ADP ratios are high

A

inhibited

70
Q

Approximately how many ATP or GTP equivalents are produced during one turn of the citric acid cycle

A

10

71
Q

In which step of the citric acid cycle is FADH2 formed

A

The conversion of succinate to fumarate

72
Q

In which reaction is ATP directly formed in the citric acid cycle

A

Conversion of succinyl CoA to succinate

73
Q

Formation of citrate from acetyl CoA and oxaloacetate is a _______ reaction

A

condensation

74
Q

Which molecule initiates the citric acid cycle by reacting with oxaloacetate

A

acetyl CoA

75
Q

The activated carrier of acyl groups is

A

Coenzyme A

76
Q

In the presence of oxygen, pyruvate is converted to

A

acetyl CoA

77
Q

Large, multi-subunit enzyme complex that links glycolysis and the citric acid cycle under aerobic conditions

A

Pyruvate dehydrogenase

78
Q

PDH is inactivated when the enzyme is

A

phosphorylated

79
Q

Caused by a deficiency in vitamin B

A

Beriberi

80
Q

The function of the citric acid cycle is to ______ high energy electrons

A

harvest

81
Q

The product found by the condensation of oxalacetate and acetyl CoA

A

6-c tricarboxylic acid

82
Q

The intermediate between citrate and isocitrate is

A

cis-aconitate

83
Q

The product of the complete oxidation of carbon in the citric acid cycle

A

CO2

84
Q

Key control points of the citric acid cycle

A
  1. Isocitrate dehydrogenase

2. ketoglutarate dehydrogenase

85
Q

The name applied to metabolic reactions that replenish the citric acid cycle intermediates that are depleted because they were used for biosynthesis

A

Anapleurotic

86
Q

Electron flow down the electron transport chain leads to

A

The transport of protons across the inner mitochondrial membrane from inside the matrix to the inter membrane space

87
Q

Coenzyme Q is also called

A

ubiquinone

88
Q

Which complex does not pump protons

A

Complex II

89
Q

What is a cytochrome

A

A protein that transfers elections and that also contains a heme prosthetic group

90
Q

The q cycle

A

transfers electrons from a two -electron carrier to a one-electrons carrier

91
Q

What pathologic conditions results from free-radical injury

A
  • emphysema
  • parkison’s disease
  • diabetes
  • atherogenesis
92
Q

Which enzyme catalyzes the reductions of o2

A

Cytochrome c oxidase

93
Q

How is light used in photosynthesis

A

The light is used to generate high-energy electrons with great reducing potential

94
Q

light absorbed by a chlorophyll causes

A

an electron to move forma ground state to an excited state

95
Q

The rotation of the ______,driven by the proton gradient, powers ATP synthesis

A

c ring

96
Q

ADP transport into the mitochondria is coupled to the export of ______

A

ATP

97
Q

Dihdroxyacetone phosphate is part of the_______ shuttle

A

glycerol 3-phosphate

98
Q

The number of ATP molecules produced by the transfer of electrons from NADH

A

2.5

99
Q

The membrane protein ________ couple the entry of ADP into the mitochondrial matrix with the exit of ATP

A

ADP-ATP translocase

100
Q

A molecular assembly in the inner mitochondrial membrane that carries out the synthesis of ATP

A

ATP synthase

101
Q

Which form of the subunit is responsible for phosphorylation of ADP

A

tight

102
Q

The proton gradient generated form the oxidation of NADH and FADH2 is called the

A

proton-motive force

103
Q

The F0 portion of ATP synthase contains the

A

proton channel

104
Q

Which form of the ATP subunit is responsible for trapping nucleotides in the subunit B

A

loose

105
Q

What type of gradient is critical to ATP formation by oxidative phosphorylation

A

proton

106
Q

When glucose is totally oxidized to CO2 and H2O, how many ATP molecules are made by oxidative phosphorylation out of a maximum yield of how many ATP molecules

A

26 out of 30

107
Q

The F1 component of ATP synthase is composed of

A
  • Three alpha subunits
  • Three beta subunits
  • Delta subunit
108
Q

The 3 beta subunits of the F1 component can exist in

A

Open, Loose, Tight

109
Q

The proton-motive force consists of

A

chemical and proton gradient

110
Q

The subunit of the ATPase embedded in the inner mitochondrial membrane is the

A

F0 subunit

111
Q

The rate of oxidative phosphorylation is determined by the need for

A

ATP

112
Q

What are the driving force for the ATP-ADP translocase

A

membrane potential from electron transport

113
Q

What is the net ATP obtained form 1 cytoplasmic NADH when it is oxidized by the ETC, using the glycerol 3-phospahte shuttle

A

1.5

114
Q

Where oxidative phosphorylation occurs in eukaryotes

A

Mitochondria

115
Q

________ is an ATP-generating process in which an inorganic substance such as oxygen serves as the ultimate electron acceptor

A

Respiration

116
Q

The electron carrier _______ is a derivative of quinine and has a isoprenoid tail

A

Coenzyme Q

117
Q

The citric acid cycle enzyme ______ is also a part of and electron-transport complex

A

Succinate dehydrogenase

118
Q

Complex_____ also know as _________ accepts electrons from NADH

A

1, NADH-Q oxidoreductase

119
Q

Complex that is not a proton pump

A

Complex 2

120
Q

A strong oxidizing agent has a strong tendency to __________ electrons

A

accept

121
Q

___________ are the result of uncontrolled electron transfer to oxygen

A

oxygen radicals

122
Q

In the cytochrome c oxidase reaction ____ protons are removed from the matrix

A

8

123
Q

In the overall stoichometry of the light reactions, 8 photons of light generate ____ molecules of ATP

A

3

124
Q

The primary photoreceptor in the chloroplasts of green plants is

A

Chlorophyll

125
Q

Photosystem 1 generates biosynthetic reducing power in the form of

A

NADPH

126
Q

Photosystem II replenishes the ________ of photosystem I while generating a _______ that is used to synthesize ______

A

Electrons, Proton Gradient, ATP

127
Q

In the light reaction of photosynthesis, the cooperation between photosystem I and photosystem II creates a flow of electrons from H2O to ____

A

NADP+

128
Q

The oxidative phase of the pentose phosphate pathway produces_____,which is required for lipid biosynthesis

A

NADPH

129
Q

The net result in sugars of the non oxidative phase of the pentose pathway is the conversion of 3______ into 2 _____ and 1_____

A

Pentoses, hexoses, Triose

130
Q

The enzyme at the committed step of the pentose phosphate pathway

A

Glucose 6- phosphate dehydrogenase

131
Q

The key source of biosynthetic reducing equivlanents

A

Pentose Phosphate Pathway

132
Q

The two key comments required for growth are _______ and biochemical reducing powers

A

Ribose sugars

133
Q

Most of the glucose residues in glycogen are linked by this bond

A

Alpha 1,4 glycoside

134
Q

The _________ enzyme catalyzes the phosphorylation of glycogen phosphorylation

A

Phosphorylase Kinase

135
Q

The hormone _____ signifies the starved or low glucose state

A

glucagon

136
Q

The ______ enzyme serves are the glucose “sensor” enzyme in liver cells

A

Phosphorylase

137
Q

Markedly increases glycogen breakdown in muscle by initiating a cAMP signal-transduction cascade

A

Epinephrine

138
Q

The hydrolysis catalyzed by a alpha-1,6 glucosidase releases a ______ molecule

A

free glucose

139
Q

_____ is the monomer that is used to extend the chain in glycogen synthesis

A

UDP-glucose

140
Q

The complete oxidation of a glucose residue from glycogen produces ____ATP

A

31

141
Q

The key regulatory enzyme in glycogen synthesis

A

Glycogen synthase

142
Q

The major site of glycogen storage

A

Liver and skeletal muscle

143
Q

The key regulatory enzyme in glycogen degradation is

A

Glycogen phosphorylase

144
Q

How is phosphorylase b converted into phosphorylase a?

A

Through the addition of a phosphate to a serine residue

145
Q

Two critical hormones that signal for glycogen breakdown are

A

glucagon and epinephrine

146
Q

What is required to remove branches in glycogen

A

debranching enzyme

transferase enzyme

147
Q

What enzyme id required to synthesize alpha-1,4-glycosidic bods in glycogen

A

glycogen synthase

148
Q

The enzyme that begins the kinase cascade, activating glycogen degradation

A

protein phosphatase 1

149
Q

What happens after a carbohydrate rich meal?

A

blood-glucose levels rise, leading to glycogen storage in the liver