Question 1

Which of the following is an electron transfer molecule in photosynthesis light reactions?

Accepted Answer

A)  plastoquinone 
B)  photon 
C)  paraquat 
D)  ATP 
A)  plastoquinone 
B)  photon 
C)  paraquat 
D)  ATP

Question 2

The herbicide paraquat operates by stealing electrons from photosystem I (PSI). Which of the following is true of chloroplasts treated with paraquat?

Accepted Answer

A)  NADPH levels drop. 
B)  Photosystem II is not re-reduced. 
C)  Plastocyanin has nowhere to donate electrons. 
D)  No protons are pumped across the chloroplast membranes. 
A)  NADPH levels drop. 
B)  Photosystem II is not re-reduced. 
C)  Plastocyanin has nowhere to donate electrons. 
D)  No protons are pumped across the chloroplast membranes.

Question 3

Use the figure below to show how light exposure results in an activated rubisco enzyme.

Accepted Answer

@#IMG-DLM& As sunlight activates the light reactio

Question 4

The Biosphere 2 project, in Tucson, Arizona, was an experiment involving a large sealed terrarium with humans and photosynthetic plants living in balance. Why did the project have to be interrupted after only a few months?

Accepted Answer

A)  Levels of CO2 rose to dangerous levels. 
B)  The humans ran out of food. 
C)  The plants stopped producing oxygen. 
D)  The rate of photosynthesis was too high. 
A)  Levels of CO2 rose to dangerous levels. 
B)  The humans ran out of food. 
C)  The plants stopped producing oxygen. 
D)  The rate of photosynthesis was too high.

Question 5

When transketolase acts on fructose-6-phosphate and glyceraldehyde-3-phosphate, the products are

Accepted Answer

A)  3-phosphoglycerate and two molecules of glyceraldehyde-3-phosphate. 
B)  dihydroxyacetone phosphate and glucose-6-phosphate. 
C)  xylulose-5-phosphate and erythrose-4-phosphate. 
D)  xylulose-5-phosphate and ribose-5-phosphate. 
A)  3-phosphoglycerate and two molecules of glyceraldehyde-3-phosphate. 
B)  dihydroxyacetone phosphate and glucose-6-phosphate. 
C)  xylulose-5-phosphate and erythrose-4-phosphate. 
D)  xylulose-5-phosphate and ribose-5-phosphate.

Question 6

In C3 plants CO2 is first incorporated into , whereas in C4 and CAM plants the CO2 is first incorporated into _.

Accepted Answer

A)  3-phosphoglycerate; oxaloacetate 
B)  dihydroxyacetone phosphate; malate 
C)  3-phosphoglycerate; malate 
D)  glyceraldehyde-3- phosphate; erythrose-4-phosphate 
A)  3-phosphoglycerate; oxaloacetate 
B)  dihydroxyacetone phosphate; malate 
C)  3-phosphoglycerate; malate 
D)  glyceraldehyde-3- phosphate; erythrose-4-phosphate

Question 7

On excitation by a photon, a fate of the excited chlorophyll molecule is to

Accepted Answer

A)  transfer an electron to an acceptor molecule. 
B)  transfer an electron to ATP. 
C)  relax and release a proton to a neighboring chlorophyll. 
D)  relax and accept an electron from a nearby donor. 
A)  transfer an electron to an acceptor molecule. 
B)  transfer an electron to ATP. 
C)  relax and release a proton to a neighboring chlorophyll. 
D)  relax and accept an electron from a nearby donor.

Question 8

The three stages of the Calvin cycle are

Accepted Answer

A)  (1) fix CO2, (2) make a C3 sugar, and (3) make glucose. 
B)  (1) fix CO2, (2) use NADPH and ATP, and (3) regenerate the starting C5 molecule. 
C)  (1) use ATP, NADPH, and CO2, (2) make a C3 molecule, and (3) regenerate the starting C3 molecule. 
D)  (1) use a C5 sugar, (2) reduce CO2 with NADPH, and (3) use ATP to regenerate the starting C5 molecule. 
A)  (1) fix CO2, (2) make a C3 sugar, and (3) make glucose. 
B)  (1) fix CO2, (2) use NADPH and ATP, and (3) regenerate the starting C5 molecule. 
C)  (1) use ATP, NADPH, and CO2, (2) make a C3 molecule, and (3) regenerate the starting C3 molecule. 
D)  (1) use a C5 sugar, (2) reduce CO2 with NADPH, and (3) use ATP to regenerate the starting C5 molecule.

Question 9

Which of the following is true of stage 2 of the Calvin cycle?

Accepted Answer

A)  Stage 2 involves the net incorporation of CO2 into the six-carbon glucose molecule. 
B)  Almost all of the NADPH and ATP from the light reactions are used in stage 2. 
C)  Stage 2 reactions are localized on the thylakoid membrane of the chloroplasts. 
D)  C3, C4, C5, and C6 sugars are all involved in stage 2 reactions. 
A)  Stage 2 involves the net incorporation of CO2 into the six-carbon glucose molecule. 
B)  Almost all of the NADPH and ATP from the light reactions are used in stage 2. 
C)  Stage 2 reactions are localized on the thylakoid membrane of the chloroplasts. 
D)  C3, C4, C5, and C6 sugars are all involved in stage 2 reactions.

Question 10

Draw the reaction that corresponds to the energy transfer between an excited chlorophyll molecule and its neighbor.

Accepted Answer

Chl₁* + C

Question 11

Which is NOT a correct analogy between the photosynthetic PQ cycle and the mitochondrial electron transport chain Q cycle?

Accepted Answer

A)  Plastocyanin is analogous to cytochrome c. 
B)  Plastoquinone is analogous to coenzyme Q. 
C)  Cytochrome b6f is analogous to Complex III. 
D)  Photosystem I is analogous to Complex I. 
A)  Plastocyanin is analogous to cytochrome c. 
B)  Plastoquinone is analogous to coenzyme Q. 
C)  Cytochrome b6f is analogous to Complex III. 
D)  Photosystem I is analogous to Complex I.

Question 12

In what location of the cell does the Calvin cycle occur?

Accepted Answer

A)  chloroplast grana 
B)  thylakoid lumen 
C)  chloroplast stroma 
D)  cytoplasm 
A)  chloroplast grana 
B)  thylakoid lumen 
C)  chloroplast stroma 
D)  cytoplasm

Question 13

Which of the following is NOT required to activate rubisco?

Accepted Answer

A)  carbamate formation of the active site lysine 
B)  activation by CO2 
C)  binding of the biotin cofactor 
D)  binding of Mg2+ 
A)  carbamate formation of the active site lysine 
B)  activation by CO2 
C)  binding of the biotin cofactor 
D)  binding of Mg2+

Question 14

Label the parts of the chloroplast on the figure below.

Accepted Answer

The answer of Label the parts of the chloroplast on...

Question 15

The formation of one net glyceraldehyde-3-phosphate during the net Calvin cycle reactions requires __________ NADPH and ATP.

Accepted Answer

A)  3; 3 
B)  3; 6 
C)  6; 6 
D)  6; 9 
A)  3; 3 
B)  3; 6 
C)  6; 6 
D)  6; 9

Question 16

Which is a way that light controls the Calvin cycle activity?

Accepted Answer

A)  Calvin cycle enzymes are inhibited by the lower H+, which is pumped out of the stroma by light reactions. 
B)  Reduced ferredoxin from the light reactions keeps thioredoxin reduced, which keeps Calvin cycle enzymes in an active form. 
C)  High levels of ATP and NADPH from the light reactions inhibit the Calvin cycle enzymes. 
D)  Calvin cycle or dark reaction enzyme activators are present at higher levels in the dark. 
A)  Calvin cycle enzymes are inhibited by the lower H+, which is pumped out of the stroma by light reactions. 
B)  Reduced ferredoxin from the light reactions keeps thioredoxin reduced, which keeps Calvin cycle enzymes in an active form. 
C)  High levels of ATP and NADPH from the light reactions inhibit the Calvin cycle enzymes. 
D)  Calvin cycle or dark reaction enzyme activators are present at higher levels in the dark.

Question 17

Per O2 molecule generated in photosynthesis light reactions, approximately how many protons are moved across the thylakoid membrane?

Accepted Answer

A)  3 
B)  4 
C)  8 
D)  12 
A)  3 
B)  4 
C)  8 
D)  12

Question 18

Electrons from plastocyanin are passed on to

Accepted Answer

A)  P700+. 
B)  P680+. 
C)  cytochrome b6f. 
D)  O2. 
A)  P700+. 
B)  P680+. 
C)  cytochrome b6f. 
D)  O2.

Question 19

The following picture is an example of what phenomenon?

Accepted Answer

A)  resonance energy transfer 
B)  electron transfer 
C)  photoexcitation 
D)  fluorescence 
A)  resonance energy transfer 
B)  electron transfer 
C)  photoexcitation 
D)  fluorescence

Question 20

The term greenhouse effect refers to the idea that

Accepted Answer

A)  the global production of plant matter is increasing. 
B)  the capacity of the earth's plant matter to store CO2 is increasing. 
C)  the temperature of the earth is increasing because of heat trapped by gases such as CO2. 
D)  tropical rainforests are gradually being eliminated. 
A)  the global production of plant matter is increasing. 
B)  the capacity of the earth's plant matter to store CO2 is increasing. 
C)  the temperature of the earth is increasing because of heat trapped by gases such as CO2. 
D)  tropical rainforests are gradually being eliminated.

Exam 12: Photosynthesis

Which of the following is an electron transfer molecule in photosynthesis light reactions?

The herbicide paraquat operates by stealing electrons from photosystem I (PSI). Which of the following is true of chloroplasts treated with paraquat?

Use the figure below to show how light exposure results in an activated rubisco enzyme.

The Biosphere 2 project, in Tucson, Arizona, was an experiment involving a large sealed terrarium with humans and photosynthetic plants living in balance. Why did the project have to be interrupted after only a few months?

When transketolase acts on fructose-6-phosphate and glyceraldehyde-3-phosphate, the products are

In C3 plants CO2 is first incorporated into , whereas in C4 and CAM plants the CO2 is first incorporated into _.

On excitation by a photon, a fate of the excited chlorophyll molecule is to

The three stages of the Calvin cycle are

Which of the following is true of stage 2 of the Calvin cycle?

Draw the reaction that corresponds to the energy transfer between an excited chlorophyll molecule and its neighbor.

Which is NOT a correct analogy between the photosynthetic PQ cycle and the mitochondrial electron transport chain Q cycle?

In what location of the cell does the Calvin cycle occur?

Which of the following is NOT required to activate rubisco?

Label the parts of the chloroplast on the figure below.

The formation of one net glyceraldehyde-3-phosphate during the net Calvin cycle reactions requires __________ NADPH and ATP.

Which is a way that light controls the Calvin cycle activity?

Per O2 molecule generated in photosynthesis light reactions, approximately how many protons are moved across the thylakoid membrane?

Electrons from plastocyanin are passed on to

The following picture is an example of what phenomenon?

The term greenhouse effect refers to the idea that

Principles of Biochemistry

Physical Biochemistry: Energy Conversion, Water, and Membranes

Nucleic Acid Structure and Function

Protein Structure

Methods in Protein Biochemistry

Protein Function

Enzyme Mechanisms

Cell Signaling Systems

Glycolysis: a Paradigm of Metabolic Regulation

The Citrate Cycle

Oxidative Phosphorylation

Carbohydrate Structure and Function

Carbohydrate Metabolism

Lipid Structure and Function

Lipid Metabolism

Amino Acid Metabolism

Nucleotide Metabolism

Metabolic Integration

DNA Replication, Repair, and Recombination

RNA Synthesis, Processing, and Gene Silencing

Protein Synthesis, Posttranslational Modification, and Transport

Gene Regulation

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In C₃ plants CO₂ is first incorporated into , whereas in C₄ and CAM plants the CO₂ is first incorporated into _.

Per O₂ molecule generated in photosynthesis light reactions, approximately how many protons are moved across the thylakoid membrane?