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Biochemistry > Exam 3 Practice Questions > Flashcards

Exam 3 Practice Questions Flashcards

1
Q

Where does glycolysis occur in a eukaryotic cell?

A

The cytoplasm

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2
Q

In glycolysis, what type of enzyme catalyzes the conversion of glucose-6-phosphate?

A

A kinase

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3
Q

Define Kinase

A

An enzyme involved in phosphoryl group transfer

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4
Q

In glycolysis, what type of enzyme catalyzes the conversion of glucose-6-phosphate to fructose-6-phosphate?

A

An isomerase

isomerase: Conversion between isomers

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5
Q

In glycolysis, how many ATP are required to convert 1 molecule of glucose to a molecule of glyceraldehyde-3-phosphate and dihydroxyacetone phosphate?

A

2 ATP required

*** At this point, no ATP have been generated

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6
Q

In glycolysis, 1,3-biphosphoglycerate is converted to 3-phosphoglycerate by the enzyme phosphoglycerate kinase. What other reaction is coupled to this process?

A

ADP –> ATP

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7
Q

The net reaction of 1 glucose molecule that is converted to 2 molecules of pyruvate results in the production of how many molecules of NADH?

A

2

This reaction happens 2x per glucose

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8
Q

The net reaction of 1 glucose molecule that is converted to 2 molecules of pyruvate results i the NET production of how many molecules of ATP?

A

2 molecules of ATP

= -2 molecules of ATP expended
+4 molecules of ATP generated.

Total yield = 2

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9
Q

In the presence of 02, pyruvate will be converted predominantly to which molecule?

A

Acetyl CoA

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10
Q

What is the most direct purpose of the conversion of pyruvate to ethanol under anaerobic conditions in organisms that do fermentation?

A

To regenerate NAD+

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11
Q

Gluconeogenesis utilizes a lot of the same reactions as glycolysis but in reverse. There are however a few unique steps in the gluconeogenesis pathway. What intermediate is seen in the pathway of gluconeogenesis that is not seen in glycolosis?

A

Oxaloacetate

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12
Q

In the Cori cycle, _____ is converted to _____ in the liver

A

Lactate, glucose

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13
Q

In gluconeogensis, fructose 1,6-biphosphate is converted to fructose-6-phosphate by what class of enzyme?

A

phosphatase

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14
Q

When pyruvate is converted to acetyl CoA, what are the other products of the reaction?

A

NADH and CO2

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15
Q

Coenzyme A contains what organic functional group that binds acetyl groups?

A

Thiol

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16
Q

The condensation of acetyl CoA with oxaloacetate to form citrate is catalyze by what type of enzyme?

A

Synthase

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17
Q

The oxidation of isocitrate to form alpha-ketoglutarate is catalyze by what type of enzyme?

A

Dehydrogenase

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18
Q

How many CO2 are released for every acetyl CoA that is metabolized via the TCA cycle?

A

2

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19
Q

Approximately how many equivalents of ATP are generated (both directly and indirectly) per every acetyl CoA that is metabolized via the TCA cycle?

A

10 equivalents

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20
Q

A function of the glyoxylate cycle is:

A

to allow acetyl CoA to be converted into glucose

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21
Q

Complexes I, II, and III of the electron transport chain all contain what common cofactor?

A

Fe-S clusters

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22
Q

Which complexes in the electron transport chain contribute to the proton gradient that is established across the inner mitochondrial membrane?

A

Complexes I, III, And IV

NOT II

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23
Q

How many electrons are required to reduce 1 molecule of O2 to 2 molecules of H2O?

A

4

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24
Q

In the Boyer binding change mechanism for ATP synthase, proton passage through the protein complex results in ________

A

rotation of the Y subunit

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25
Q

Which form of electromagnetic radiation would have the highest energy per photon?
red vl, violet vl, in waves, microwaves, radio waves

A

Violet visible light

chart as follows lowest to highest energy:(lowest) rad, mic, in waves, R O Y G B V (highest)

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26
Q

Electrons are transferred from the special pair of chlorophyll molecules in photosystem II p680 most directly to which molecule?

A

plastoquinone

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27
Q

The water oxidizing complex, or oxygen evolving complex, contains which metal ion cofactor?

A

Manganese (Mn)

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28
Q

In the series of light dependent reactions, electrons are ultimately transferred from ________-

A

H20 to NADP+

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29
Q

If one mol of O2 was produced via the light dependent reactions in photosynthesis, how many mol of NADPH were produced?

A

2

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30
Q

Which scientist determined the series of steps for the reduction of CO2 to glucose in photosynthetic organisms?

A

Calvin

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31
Q

How many molecules of ATP and NADPH would be required to fix 6 molecules of CO2 via the Calvin cycle?

A

18 ATP, 12 NADPH

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32
Q

How many molecules of ATP and NADPH are required to fix 1 molecule of Co2 via the calvin cycle?

A

3 ATP 2 NADPH

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33
Q

The first step in the storage of glucose as glycogen is the conversion of glucose-6-phosphate to glucose-1-phosphate. What type of enzyme catalyzes this reaction?

A

Mutase

Mutase: catalyzes shift of functional group from one position to another within the same molecule

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34
Q

Glycogen synthase and glycogen phosphorylase are regulated by phosphorylation and coordinate regulation.
Which of the scenarios below could describe the coordinate regulation of these two enzymes?

A

phosphorylation activates glycogen phosphorylase while making glycogen synthase less active.
De-phosphorylation activates glycogen synthase while making glycogen phosphorylase less active

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35
Q

One function of the pentose pathway is to:

A

make NADPH

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36
Q

The reactions of glycolysis convert one molecule of glucose to _____.

A

2 molecules of pyruvate

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37
Q

Describe the group of enzymes termed kinases:

A

Kinases catalyze the transfer of a phosphoryl group from one molecule to another

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38
Q

Define phosphates

A

Phosphatases catalyze the removal of a phosphoryl group from a substrate

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39
Q

Define mutases:

A

Mutases catalyze the intramolecular transfer of a phosphate group from one position to another on a substrate molecule.

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40
Q

Define dehydrogenases

A

dehydrogenases catalyze the transfer of electrons between two substrates

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41
Q

define isomerases

A

isomerases catalyze the interconversion of two isomers

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42
Q

In glycolysis, what type of enzymes catalyzes the conversion of glyceraldehyde-3-phosphate to 1,3-biphosphoglycerate

A

dehydrogenase

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43
Q

in the conversion of fructose-6-phosphate to fructose-1,6-bisphosphate, what other molecule serves as a cosubstrate?

A

ATP

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44
Q

The conversion of 1 molecule of glucose to 2 molecules of pyruvate results in a net release of how many molecules of CO2?

A

0

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45
Q

What is the function of glyceraldehyde-3-phosphate dehydrogenase? (Hint: You do not need to know the specific reaction catalyzed by this enzyme to answer this question.)

A

oxidation by NAD+ to form NADH and an acyl-phosphate

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46
Q

The regeneration of ____ in the reduction of pyruvate to lactate sustains glycolysis under anaerobic conditions.

A

NAD+

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47
Q

In the gluconeogenesis pathway, the conversion of pyruvate to phosphoenolpyruvate involves all of the following as substrates or products except ______.

A

NADH

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48
Q

What is the major tissue in which gluconeogenesis takes place?

A

liver

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49
Q

CoA contains what functional organic group that binds acetyl groups?

A

thiol

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50
Q

Pyruvate dehydrogenase catalyzes the conversion of pyruvate to acetyl-CoA. Another product in this reaction is _____

A

NADH

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51
Q

Pyruvate dehydrogenase catalyzes the conversion of pyruvate to acetyl-CoA. Another product in this reaction is ____

A

CO2

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52
Q

Which of the following is not a cofactor or cosubstrate of pyruvate dehydrogenase?

A

ATP

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53
Q

What is the first step of the TCA cycle?

A

Condensation of acetyl-CoA with oxaloacetate to form citrate

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54
Q

Which enzyme catalyzes the condensation of acetyl-CoA with oxaloacetate to form citrate

A

citrate synthase

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55
Q

What is a synthase?

A

enzyme that catalyzes the linking of two molecules

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56
Q

What does TCA cycle stand for?

A

Tri carboxylic acid cycle

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57
Q

What is the second step of the TCA cycle?

A

The rearrangement of citrate to isocitrate

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58
Q

What is aconitase?

A

A moonlighting enzyme that has a cofactor for Fe-S clusters

***this is important as 1. it regulates this step (2) of the TCA cycle and 2. the protein synthesis in iron transfer into the cell and iron storage

  • Iron in your cells is not a good thing, typically bound to ferritin, apoaconitase can make ferritin
    moonlighting: two different jobs within the cell
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59
Q

In the next step of the TCA cycle (3), isocitrate and NAD+ are converted to a-ketoglutarate and NADH.
What type of enzyme do you think catalyzes the reaction?

A

Dehydrogenase

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60
Q

In the conversion of isocitrate to a-ketogluatarate (3), what happens?

A

2 electron oxidation couples to reduction of NAD+

Release of CO2

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61
Q

What is the function of a dehydrogenase?

A

Catalyze oxidation-reduction reactions by transferring electrons to electron acceptor

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62
Q

How many carbons are in isocitrate?

A

6

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63
Q

How many carbons are in a-ketoglutarate?

A

5

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64
Q

What is step 4 of the TCA cycle?

A

The conversion of a-ketoglutarate to succinyl CoA

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65
Q

What happens in step 4 of the TCA cycle?

A

2 electron oxidation couple to reduction of NAD+
Release of CO2
Formation of thioester bond with CoA

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66
Q

How many Carbons does succinyl CoA contain?

A

4

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67
Q

What are the 3 elements of the a-ketoglutarate dehydrogenase complex?

A

TPP
Lipoamide
FAD

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68
Q

What happens in step 5-end of the TCA cycle?

A

Succinyl CoA is converted back to oxaloacetate

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69
Q

In the next step of the TCA cycle, succinyl CoA (which contains a high potential energy thioester bond) is converted to succinate. What other reaction would you predict may be couples to this process?

A

ADP + P(i) –> ATP

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70
Q

What is the only step in the TCA cycle where substrate level phosphorylation occurs?

A

Succinyl CoA to succinate

***only step that yield GTP (ATP) directly

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71
Q

In the next step of the TCA cycle, succinate and FAD are converted to fumarate and FADH2. What types of enzyme do you think catalyzes this reaction?

A

dehydrogenase

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72
Q

What occurs in the succinate to fumarate part of the TCA cycle?

A

2 electron oxidation couples to reduction of FAD

Succinate dehydrogenase is embedded in the inner mitochondrial membrane (Complex II)

this serves as a direct link to the tca cycle and oxidative phosphorylation

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73
Q

In the last step of the TCA cycle, malate is converted to oxaloacetate, what happens?

A 
2 electron oxidation coupled to reduction of NAD+
ATP: 1
NADH: 3
FADH2: 1
CO2:2
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74
Q

In the net overall TCA cycle, what is produced per glucose?

A

4 CO2
6NADH
2 FADH2
2 GTP (ATP)

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75
Q

How many electrons does it take to fully oxidize our carbon?

A

24

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76
Q

T/F The reactions of the electron transport chain can be uncoupled form ATP synthesis.

A

True, this is found in animals with brown adipose tissue.
Mitochondria contain UCP-1 that transports H+ to the matrix without the concurrent synthesis of ATP-short circuits the mitochondrial proton “battery”

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77
Q

This is the name given to the hypothesis proposed by Peter Mitchell to explain how ATP synthesis is coupled to electron transport.

A

Chemiosmotic theory

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78
Q

If 4 mol of H+ move through ATP synthase for each ATP that is produced, the how many mol of ATP are made for each 1 mol of NADH oxidized?

A

2.5 mol ATP per 1/NADH

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79
Q

ATP synthase of the mitochondrial electron transport chain uses the energy contained in the H+ gradient to ______

A

release ATP bound to the complex after synthesis

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80
Q

Define photosynthesis:

A

The transformation of electromagnetic energy to chemical energy

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81
Q

What happens in light reactions?

A

oxidation of water to produce O2 coupled to the reduction of NADP+ to make NADPH

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82
Q

What are light reactions used for?

A
  • transfer of electrons also coupled to the movement of H+ across the membrane
  • proton gradient used to synthesize ATP
  • some organisms use electron donors other than H2O
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83
Q

What are photosynthetic pigments?

A

molecules capable of absorbing the energy of light of a specific wavelength

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84
Q

T/F objects appear the color of the light that is reflected (not the light that is absorbed)

A

True

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85
Q

The inner membrane of the chloroplast surrounds a space called the _____

A

stroma

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86
Q

How many moles of O2 are evolved in the plant light reactions for each mole of NADPH produced?

A

0.5

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87
Q

One of the functions of cytochrome b6f in the plant photosynthesis system is to ________

A

translocate protons across the thylakoid membrane

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88
Q

The portion of the photosystem II complex that acts directly to oxidize water is ______

A

Mn cluster

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89
Q

Photosystem I directly oxidizes what molecule?

A

Plastocyanin

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90
Q

Where does the calvin cycle occur?

A

the stroma of chloroplasts

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91
Q

How many stages of the calvin cycle are there?

A

3

92
Q

What are the three stages of the calvin cycle?

A
  1. fixation of CO2 to 3-phosphoglycerate
  2. reduction of 3-phosphoglycerates to hexose sugars
  3. regeneration of ribulose 5-phosphate
93
Q

Where does the citric acid cycle (TCA cycle) take place in the cell?

A

mitochondria

94
Q

What enzyme is responsible for the following reaction?

pyruvate + CoA + NAD+ —–> acetyl-CoA + NADH + H+ + CO2

A

pyruvate dehydrogenase

95
Q

Isocitrate is oxidized to alpha-ketoglutarate with the concomitant reduction of NAD+ to NADH. What type of enzyme catalyzes this reaction?

A

dehydrogenase

96
Q

The net yield from one mole of acetyl-CoA that completes the TCA cycle is (i) how many NADH, (ii) how many FADH2, and (iii) how many moles of GTP (or equivalents of ATP)?

A

(i) 3 (ii) 1 (iii) 1

97
Q

Which of the following is true about the glyoxylate cycle?

A

It provides a way to use acetyl-CoA for the net production of succinate and malate that can than ultimately be used to make glucose.

98
Q

Which of the following is not a cofactor or co-substrate for pyruvate dehydrogenase?

thiamine pyrophosphate, lipoic acid, FAD, Fe2+, Coenzyme A

A

Fe2+

99
Q

The first step in the TCA cycle is the condensation of acetyl-CoA with what molecule?

A

oxaloacetate

100
Q

For each acetyl-CoA that is oxidized completely via the TCA cycle, how many CO2 are released?

A

2

101
Q

The conversion of succinate to fumarate is a(n) ______ half reaction. (Use the reference sheet for the exam to help you.)

A

oxidation

102
Q

Which cofactor is present in Complex I, Complex II and Complex III in the electron transport chain?

A

FeS clusters

103
Q

Which molecule carries electrons from Complex III to Complex IV?

A

cytochrome c

104
Q

Which best describes a cytochrome?

A

a protein that transfers electrons and that also contains a heme cofactor

105
Q

Transfer of electrons from NADH using the electron transport chain results in approximately how many ATP per NADH?

A

2.5

106
Q

A portion of ATP synthase in the mitochondrial membrane synthesizes ATP by spinning like a top. The energy to spin this “top” directly comes from __________.

A

the proton concentration difference from the outside to the inside of the membrane

107
Q

Which enzyme catalyzes the reduction of O2?

A

cytochrome c oxidase

108
Q

Which of the following does not pump protons?

A

Complex II

109
Q

What metal ion does chlorophyll contain?

A

Mg

110
Q

Which form of electromagnetic radiation has the highest amount of energy per photon?

ultraviolet, visible green light, visible red light, microwaves

A

ultraviolet

111
Q

The transfer of excitation energy from one molecule to one nearby through electromagnetic interaction (no transfer of electrons) is called _________.

A

resonance energy transfer

112
Q

Light absorption induces electron transfer from photosystem II most directly to which molecule?

A

plastoquinone

113
Q

Which metal ion does plastocyanin contain?

A

Cu

114
Q

Which of the following is not an output of photosynthesis?

NADPH, O2, carbohydrates, CO2

A

CO2

115
Q

How is light energy used in photosynthesis?

A

Light energy is used to generate high energy electrons that can be transferred to NADP+.

116
Q

In photosynthesis, which complex moves protons across the membrane?

A

cytochrome b6f

117
Q

In glycolysis, how many ATP are required to convert 1 molecule of glucose to a molecule of glyceraldehyde-3-phosphate and dihydroxyacetone phosphate?

A

2 ATP required

118
Q

In glycolysis, 1,3-bisphosphoglycerate is converted to 3-phosphoglycerate by the enzyme phosphoglycerate kinase. What other reaction is coupled to this process?

A

ADP → ATP

119
Q

The net reaction of 1 glucose molecule that is converted to 2 molecules of pyruvate results in the production of how many molecules of NADH?

A

2

120
Q

The net reaction of 1 glucose molecule that is converted to 2 molecules of pyruvate results in the NET PRODUCTION of how many molecules of ATP?

A

2

121
Q

In the presence of oxygen (O2), pyruvate will be converted predominantly to which molecule?

A

acetyl CoA

122
Q

What is the most direct purpose of the conversion of pyruvate to ethanol under anaerobic conditions in organisms that do fermentation?

A

to regenerate NAD+

123
Q

In gluconeogenesis, fructose 1,6-bisphosphate is converted to fructose-6-phosphate by what class of enzyme?

A

phosphatase

124
Q

When pyruvate is converted to acetyl CoA, what are the other products of the reaction?
ATP, NADH, or CO2

A

both (b) and (c)

NADH and CO2

125
Q

Coenzyme A contains what organic functional group that binds acetyl groups?

A

Thiol

126
Q

The condensation of acetyl CoA with oxaloacetate to form citrate is catalyzed by what type of enzyme?

A

synthase

127
Q

The oxidation of isocitrate to form α-ketoglutarate is catalyzed by what type of enzyme?

A

dehydrogenase

128
Q

How many CO2 are released for every acetyl CoA that is metabolized via the TCA cycle?

A

2

129
Q

Approximately how many equivalents of ATP are generated (both directly and indirectly) per every acetyl CoA that is metabolized via the TCA cycle?

A

10

130
Q

A function of the glyoxylate cycle is __________.

A

to allow acetyl CoA to be converted into glucose

131
Q

Complexes I, II and III of the electron transport chain all contain what common cofactor?

A

Fe-S clusters

132
Q

Which complexes in the electron transport chain contribute to the proton gradient that is established across the inner mitochondrial membrane?

A

Complexes I, III, and IV

133
Q

How many electrons are required to reduce 1 molecule of O2 to 2 molecules of H2O?

A

4

134
Q

The water oxidizing complex, or oxygen evolving complex, contains which metal ion cofactor?

A

Mn (manganese)

135
Q

In the series of light dependent reactions, electrons are ultimately transferred from ______.

A

H2O to NADP+

136
Q

If one mol of O2 was produced via the light dependent reactions in photosynthesis, how many mol of NADPH were produced?

A

2

137
Q

Which scientist determined the series of steps for the reduction of CO2 to glucose in photosynthetic organisms?

A

Calvin

138
Q

How many molecules of ATP and NADPH would be required to fix 6 molecules of CO2 via the Calvin cycle?

A

18 ATP and 12 NADPH

139
Q

The first step in the storage of glucose as glycogen is the conversion of glucose-6-phosphate to glucose-1-phosphate. What type of enzyme catalyzes this reaction

A

mutase

140
Q

Glycogen synthase and glycogen phosphorylase are regulated by phosphorylation and coordinate regulation. Which of the scenarios below could describe the coordinate regulation of these two enzymes?

A

(c) Phosphorylation activates glycogen phosphorylase while making glycogen synthase less active.
(d) De-phosphorylation activates glycogen synthase while making glycogen phosphorylase less active.

141
Q

One function of the pentose phosphate pathway is to _______.

A

Make NADPH

142
Q

The reactions of glycolysis convert one molecule of glucose to __________.

A

2 molecules of pyruvate

143
Q

Which of the following below best describes the group of enzymes known as kinases?

A

Kinases catalyze the transfer of a phosphoryl group from one molecule to another.

144
Q

In glycolysis, what type of enzyme catalyzes the conversion of glyceraldehyde-3-phosphate to 1,3-bisphosphoglycerate?

A

dehydrogenase

145
Q

In the conversion of fructose-6-phosphate to fructose-1,6-bisphosphate, what other molecule serves as a cosubstrate?

A

ATP

146
Q

In the conversion of glucose to pyruvate, how many molecules of CO2 are released?

A

0

147
Q

Which reaction below does not require ATP as a cosubstrate?

glucose → glucose-6-phosphate

fructose-6-phosphate → fructose-1,6-bisphosphate

glyceraldehyde-3-phosphate → 1,3-bisphosphoglycerate

All of the above reactions require ATP as a cosubstrate.

None of the above reactions require ATP as a cosubstrate.

A

glyceraldehyde-3-phosphate → 1,3-bisphosphoglycerate

148
Q

Which of the following intermediates in glycolysis have a higher phosphoryl transfer potential than ATP? (Which molecules are capable of donating a phosphate group to ADP to form ATP?)

(a) fructose-1,6-bisphosphate
(b) 1,3-bisphosphoglycerate
(c) phosphoenolpyruvate

A

1,3-bisphosphoglycerate

(c) phosphoenolpyruvate

149
Q

Under anaerobic conditions pyruvate will be converted to which molecule?

A

lactate or ethanol depending on the organism

150
Q

What is the primary purpose of the conversion of pyruvate to lactate in muscle tissue?

A

to regenerate NAD+ for use in glycolysis

151
Q

Gluconeogenesis utilizes a lot of the same reactions and enzymes as glycolysis but in reverse, however a few of the reactions are irreversible. Which class of enzymes is part of the gluconeogenesis pathway that is NOT part of the glycolysis pathway?

A

phosphatases

152
Q

In gluconeogenesis, how many nucleoside triphosphates are required to convert one molecule of pyruvate to one molecule of phosphoenolpyruvate?

A

2

153
Q

In the Cori cycle lactate is transported from the ___(i)___ to the ___(ii)___.

A

(i) muscle (ii) liver

154
Q

The conversion of one pyruvate molecule to one acetyl-CoA molecule releases how many molecules of CO2?

A

1

155
Q

What is the cellular location of the TCA cycle reactions in eukaryotes?

A

mitochondrial matrix

156
Q

In the TCA cycle, malate is oxidized to oxaloacetate. What type of enzyme catalyzes this reaction?

A

dehydrogenase

157
Q

Which reaction below is the only TCA cycle reaction that yields ATP directly via substrate level phosphorylation?

A

succinyl-CoA → succinate

158
Q

How many TCA cycle reactions release CO2 as a product?

A

2

159
Q

Under aerobic conditions, each molecule of glucose is converted to how many acetyl-CoA molecules that can be fully oxidized via the TCA cycle reactions?

A

2

160
Q

Which of the following is a true statement regarding the glyoxylate cycle?

The glyoxylate cycle allows for net conversion of acetyl-CoA to oxaloacetate.

The glyoxylate cycle reactions bypass the reactions of the TCA cycle that release carbon as CO2.

Humans lack a glyoxylate pathway.

A

All are true

161
Q

Where are the enzymes involved in the electron transport chain located in a eukaryotic cell?

A

inner mitochondrial membrane

162
Q

Which of the following describes the pathway of electrons from NADH through the electron transport chain?

A

Complex I – Q – Complex III – cytochrome c – Complex IV

163
Q

Complex IV of the electron transport chain contains which of the following cofactors?
(a) cytochrome hemes
(b) Cu2+
(c) Fe-S clusters
Complex IV contains all of the above cofactors.

A

Complex IV contains only (a) and (b) as cofactors.

164
Q

Complex IV of the electron transport chain oxidizes ___(i)___ and reduces ___(ii)___.

A

(i) cytochrome c (ii) O2

165
Q

Brown adipose tissue (brown fat) contains UCP-1, an uncoupling protein that uncouples the electron transport chain from ATP synthase. How does this affect the amount of ATP generated by a cell?

A

UCP-1 allows the transport of H+ back into the mitochondrial matrix without the requirement of passage through ATP synthase resulting in lower levels of ATP synthesized.

166
Q

Of visible light, which color of electromagnetic radiation would have the lowest energy per photon?

A

red light

167
Q

Which term best describes the following process: An electron in a photoreceptor molecule absorbs a photon of energy, is promoted to an excited state, and transfers the energy to an electron in a nearby molecule upon returning to the ground state.

A

resonance energy transfer

168
Q

In the photosynthetic light reactions, the direct electron donor to photosystem I is ______.

A

plastocyanin

169
Q

Electrons from Photosystem II are directly replaced by electrons from ______.

A

H2O

170
Q

The oxidation of 2 mol of H2O to produce 1 mol of O2 would result in the generation of how many mol of NADPH?

A

2

171
Q

The conversion of 3-phosphoglycerate to 1,3-bisphosphoglycerate in the Calvin cycle requires which molecule as a cosubstrate?

A

ATP

172
Q

How many molecules of CO2 must enter the Calvin cycle to cause a net synthesis of 1 molecule of glyceraldehyde-3-phosphate which could then be used in the production of a hexose sugar such as glucose?

A

3

173
Q

Which activated precursor is required for starch synthesis in plants?

A

ADP-glucose

174
Q

The pentose phosphate pathway in animals is essential for the production of ___(i)___ required for ___(ii)___.

A

(i) NADPH (ii) biosynthetic reactions

175
Q

In the gluconeogenesis pathway, what type of enzyme converts glucose-6-phosphate to glucose?

A

phosphatase

176
Q

Which substance must be regenerated in order for glycolysis to proceed?

A

NAD+

177
Q

What is substrate-level phosphorylation?

A

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

178
Q

The conversion of 1 molecule of glucose to 2 molecules of pyruvate results in a net release of how many molecules of CO2?

A

0

179
Q

In the gluconeogenesis pathway, what compound is formed that is not formed in the glycolytic pathway?

A

oxaloacetate

180
Q

In the gluconeogenesis pathway, what type of enzyme converts glucose-6-phosphate to glucose?

A

phosphatase

181
Q

The step of the Calvin cycle that involves the addition of CO2 to ribulose 1,5-bisphosphate to produce 2 molecules of 3-phosphoglycerate is catalyzed by what enzyme?

A

Rubisco

182
Q

How many molecules of ATP would be required to fix 6 molecules of CO2 via the Calvin cycle?

A

18

183
Q

What is the type of linkage between most of the glucose residues in glycogen?

A

α-1,4-glycosidic

184
Q

The key enzyme in glycogen degradation, which functions to cleave a glycosyl unit by addition of a phosphate group is called ____________.

A

glycogen phosphorylase

185
Q

Which molecule is a key source of reducing equivalents used in biosynthetic pathways?

A

NADPH

186
Q

Which products from the light dependent reactions of photosynthesis are used in the Calvin cycle?

A

ATP and NADPH

187
Q

How many molecules of ATP would be required to fix 6 molecules of CO2 via the Calvin cycle?

A

18

188
Q

What is the type of linkage between most of the glucose residues in glycogen?

A

α-1,4-glycosidic

189
Q

Besides glycogen phosphorylase, what other enzyme is required for glycogen degradation?

A

debranching enzyme

190
Q

The purpose of the pentose phosphate pathway is to _______.

A

(b) generate NADPH

(c) synthesize 5-carbon sugars

191
Q

The conversion of 1 glucose to 2 pyruvate requires the input of ____ ATP molecules

A

2

192
Q

One complete calvin cycle requires ___ ATP

A

3

193
Q

In the calvin cycle, CO2 is combined with

A

ribulose-1,5-diphosphoglycerate

194
Q

Plastocyanin contains ____ as a cofactor

A

Cu

195
Q

In plant light reactions, which complex reduces NADP+?

A

PSI

196
Q

In plant light reactions, the direct electron donor to photosystem II is _____

A

water

197
Q

Absorption of visible light by chlorophyll involves

A

Changes electronic states

198
Q

Chlorophyll contains ____

A

Mg

199
Q

Key outputs from phototrophs includes all of the following except _____

NADPH
O2
C(H2O)
CO2

A

CO2

200
Q

Which electron transport chain complex reduces O2?

A

Complex IV

201
Q

Cytochrome C contains what cofactor?

A

heme

202
Q

Which of the electron transport chain complexes oxidizes CoQH2?

A

Complex III

203
Q

In oxidative phosphorylation, the oxidation of 2 NADH results in the translocation of how many protons?

A

20

204
Q

In a eukaryote, the electron transport chain is located in the _______

A

mitochondrial inner membrane

205
Q

The conversion of succinyl-CoA to succinate yields ______

A

GTP

206
Q

The conversion of alpha ketoglutarate to succinyl-CoA requires ____ as a substrate

A

CoA

207
Q

One turn of the TCA cycle yields ____ NADH

A

3

208
Q

The Cori cycle describes _____

A

an interconnection between glycolysis and gluconeogenesis

209
Q

The conversion of pyruvate to ethanol has a product of _____-

A

CO2

210
Q

The conversion of phosphoenolpyruvate to pyruvate has a product of ____-

A

ATP

211
Q

One turn of the TCA cycle yields ____ CO2

A

2

212
Q 
The pre-TCA step has as substrates all of the following except \_\_\_\_-
pyruvate
CoA
NAD+
ADP
A

ADP

213
Q

The conversion of 3-phosphoglycerate to 2-phosphoglycerate is catalyzed by a _____-

A

mutase

214
Q

The conversion of 1 mol of glucose to 6 mol CO2 is a _____ electron, _____ half reaction

A

24, oxidation

215
Q

CoA binds to an acetyl group through a _____ linkage

A

Thioester

216
Q

The conversion of citrate to isocitrate in the TCA cycle is catalyzed by the enzyme aconitase, which contains _____ as a cofactor

A

FeS cluster

217
Q

Addition of __ electrons and __ protons result in the reduction of Coenzyme Q

A

2, 2

218
Q

Complex III in the mitochondrial electron transport chain oxidizes _____ and reduces ______

A

reduced coenzyme Q, cytochrome C

219
Q

Mitochondrial electron transport chain complex IV contains ______ as a cofactor that interacts with O2

A

Cu

220
Q

Beta carotene does not absorb light of approximately what wavelength?

A

700 nm

221
Q

The special pair of chlorophyll molecules in plant PSII is called

A

P680

222
Q

The part of plant PSII that directly oxidizes water is

A

the Mn4Ca complex

223
Q

The copper containing protein in the photosynthetic electron transport chain is called

A

plastocyanin

224
Q

The fixation of one CO2 in the calvin cycle utilizes ____ ATP

A

3

225
Q

The synthesis of starch in plants utilizes _____

A

ATP

Biochemistry (7 decks)

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