Question 1

What is the main difference between C4 and CAM plants?

Accepted Answer

CAM plants open up their stomata at nigh

Question 2

The final product that is formed by the enzyme rubisco is

Accepted Answer

A)  3-phosphoglycerate. 
B)  ATP. 
C)  ribulose-1,5-bisphosphate. 
D)  glyceraldehyde-3-phosphate. 
A)  3-phosphoglycerate. 
B)  ATP. 
C)  ribulose-1,5-bisphosphate. 
D)  glyceraldehyde-3-phosphate.

Question 3

The Calvin cycle requires which species from the light reactions?

Accepted Answer

A)  ATP and NADPH 
B)  reducing electrons 
C)  CO2 and ATP 
D)  NADH and FADH2 
A)  ATP and NADPH 
B)  reducing electrons 
C)  CO2 and ATP 
D)  NADH and FADH2

Question 4

Write out the overall net Calvin cycle reaction assuming three CO2 molecules are the starting reactant.

Accepted Answer

3 CO₂ + 6 NADPH + 9 A

Question 5

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

Accepted Answer

@#IMG-DLM&_TB6697_00 As sunlight activates the lig

Question 6

The first stage of the three-stage Calvin cycle

Accepted Answer

A)  generates CO2. 
B)  uses ATP and NADPH from the light reactions. 
C)  occurs in the plant cell cytoplasm. 
D)  is catalyzed by the enzyme rubisco. 
A)  generates CO2. 
B)  uses ATP and NADPH from the light reactions. 
C)  occurs in the plant cell cytoplasm. 
D)  is catalyzed by the enzyme rubisco.

Question 7

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 8

C4 plants are thought to be more efficient than C3 plants because they

Accepted Answer

A)  make larger sugar molecules from CO2. 
B)  can concentrate the CO2 in chloroplasts and therefore minimize side reactions with O2. 
C)  can produce sugar molecules at night in addition to during the day. 
D)  can live in dry climates. 
A)  make larger sugar molecules from CO2. 
B)  can concentrate the CO2 in chloroplasts and therefore minimize side reactions with O2. 
C)  can produce sugar molecules at night in addition to during the day. 
D)  can live in dry climates.

Question 9

At what stage of plant growth is the glyoxylate cycle most common,and why?

Accepted Answer

The glyoxylate cycle is most c

Question 10

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 11

Overall,the net balanced reaction of the Calvin cycle converts 3 CO2 into one

Accepted Answer

A)  ribulose-5-phosphate. 
B)  glyceraldehyde-3-phosphate. 
C)  acetyl-CoA. 
D)  glucose. 
A)  ribulose-5-phosphate. 
B)  glyceraldehyde-3-phosphate. 
C)  acetyl-CoA. 
D)  glucose.

Question 12

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 13

Which two proteins do electrons move between in the PQ cycle?

Accepted Answer

The PQ cycle moves e

Question 14

Name the two key enzymes involved in swapping carbons between sugars in the carbon shuffling reactions of stage 3 of the Calvin cycle,and describe the differences in their reactions.

Accepted Answer

Transaldolase and transketolase.Transald

Question 15

Which is the orange pigment commonly found in plant's light harvesting complexes?

Accepted Answer

A)  chlorophyll 
B)  phycocyanobilin 
C)  porphyrin 
D)  $\beta$-carotene 
A)  chlorophyll 
B)  phycocyanobilin 
C)  porphyrin 
D)  $\beta$-carotene

Question 16

Resonance energy transfer from one chlorophyll in the photosystems results in

Accepted Answer

A)  a reduced neighboring pheophytin molecule. 
B)  a neighboring chlorophyll in an excited state. 
C)  heat release. 
D)  the release of a photon. 
A)  a reduced neighboring pheophytin molecule. 
B)  a neighboring chlorophyll in an excited state. 
C)  heat release. 
D)  the release of a photon.

Question 17

Which cell type in C4 plants is isolated from O2 exposure as they perform Calvin cycle reactions?

Accepted Answer

A)  Hatch-Slack cells 
B)  bundle sheath cells 
C)  guard cells 
D)  mesophyll cells 
A)  Hatch-Slack cells 
B)  bundle sheath cells 
C)  guard cells 
D)  mesophyll cells

Question 18

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 19

The energy derived from photosynthesis and used to make ATP is manifested in what form?

Accepted Answer

A)  an acidic stroma 
B)  an electron gradient in the thylakoid membrane 
C)  an acidic thylakoid lumen 
D)  an acidic cytoplasm 
A)  an acidic stroma 
B)  an electron gradient in the thylakoid membrane 
C)  an acidic thylakoid lumen 
D)  an acidic cytoplasm

Question 20

Which enzyme in the photosynthesis light reactions does NOT transfer electrons?

Accepted Answer

A)  ATP synthase 
B)  photosystem II 
C)  photosystem I 
D)  cytochrome b6f 
A)  ATP synthase 
B)  photosystem II 
C)  photosystem I 
D)  cytochrome b6f

Exam 12: Photosynthesis

What is the main difference between C4 and CAM plants?

The final product that is formed by the enzyme rubisco is

The Calvin cycle requires which species from the light reactions?

Write out the overall net Calvin cycle reaction assuming three CO2 molecules are the starting reactant.

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

The first stage of the three-stage Calvin cycle

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

C4 plants are thought to be more efficient than C3 plants because they

At what stage of plant growth is the glyoxylate cycle most common,and why?

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

Overall,the net balanced reaction of the Calvin cycle converts 3 CO2 into one

Which of the following is NOT required to activate rubisco?

Which two proteins do electrons move between in the PQ cycle?

Name the two key enzymes involved in swapping carbons between sugars in the carbon shuffling reactions of stage 3 of the Calvin cycle,and describe the differences in their reactions.

Which is the orange pigment commonly found in plant's light harvesting complexes?

Resonance energy transfer from one chlorophyll in the photosystems results in

Which cell type in C4 plants is isolated from O2 exposure as they perform Calvin cycle reactions?

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

The energy derived from photosynthesis and used to make ATP is manifested in what form?

Which enzyme in the photosynthesis light reactions does NOT transfer electrons?

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

Filters

What is the main difference between C₄ and CAM plants?

Write out the overall net Calvin cycle reaction assuming three CO₂ molecules are the starting reactant.

C₄ plants are thought to be more efficient than C₃ plants because they

Overall,the net balanced reaction of the Calvin cycle converts 3 CO₂ into one

Which cell type in C₄ plants is isolated from O₂ exposure as they perform Calvin cycle reactions?