Question 1

Which is a characteristic of the second stage of the three-stage Calvin cycle?

Accepted Answer

A)  It uses ATP and NADPH. 
B)  It is similar to a series of reactions in pentose phosphate pathway. 
C)  It is catalyzed by an enzyme called rubisco. 
D)  It begins and ends with a C5 sugar. 
A)  It uses ATP and NADPH. 
B)  It is similar to a series of reactions in pentose phosphate pathway. 
C)  It is catalyzed by an enzyme called rubisco. 
D)  It begins and ends with a C5 sugar.

Question 2

The glyoxylate cycle reaction shown below is catalyzed by which enzyme class?

Accepted Answer

A)  lyase 
B)  hydrolase 
C)  transferase 
D)  oxidoreductase 
A)  lyase 
B)  hydrolase 
C)  transferase 
D)  oxidoreductase

Question 3

Under what condition(s)do the wasteful side reaction of O2 with rubisco become significant?

Accepted Answer

A)  higher levels of CO2 than O2 
B)  at night 
C)  increased temperature and intense light 
D)  increased rubisco concentrations 
A)  higher levels of CO2 than O2 
B)  at night 
C)  increased temperature and intense light 
D)  increased rubisco concentrations

Question 4

Approximately how many ATP are synthesized per O2 molecule generated in photosynthesis light reactions?

Accepted Answer

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

Question 5

Chlorophyll absorbs

Accepted Answer

A)  heat energy and reaches an excited state. 
B)  photon energy and becomes excited or oxidized. 
C)  an electron during photon excitation. 
D)  all wavelengths of light. 
A)  heat energy and reaches an excited state. 
B)  photon energy and becomes excited or oxidized. 
C)  an electron during photon excitation. 
D)  all wavelengths of light.

Question 6

The five-step mechanism of ribulose bisphosphate carboxylase (rubisco)

Accepted Answer

A)  is an overall thermodynamically unstable reaction. 
B)  involves C1, C3, C4, C5, and C6 molecules in the enzyme mechanism intermediates. 
C)  adds a CO2 molecule to a C5 ribulose sugar, yielding an unstable C6 molecule that cleaves into two C3 molecules. 
D)  involves the incorporation of 3 CO2 molecules to yield one 3-phosphoglycerate molecule. 
A)  is an overall thermodynamically unstable reaction. 
B)  involves C1, C3, C4, C5, and C6 molecules in the enzyme mechanism intermediates. 
C)  adds a CO2 molecule to a C5 ribulose sugar, yielding an unstable C6 molecule that cleaves into two C3 molecules. 
D)  involves the incorporation of 3 CO2 molecules to yield one 3-phosphoglycerate molecule.

Question 7

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 8

Heme and chlorophyll have the same porphyrin cofactor,yet they have largely different roles.Compare their color and the metal ions employed by each.

Accepted Answer

Chlorophyl

Question 9

What is the process depicted below,where plants react with O2?

Accepted Answer

A)  photorespiration 
B)  photosynthesis 
C)  photogeneration 
D)  photoglycolate pathway 
A)  photorespiration 
B)  photosynthesis 
C)  photogeneration 
D)  photoglycolate pathway

Question 10

Trace the electron from plastocyanin to NADPH in the photosynthetic electron transport system.

Accepted Answer

See Figure 12.30 below.plastocyanin @#IMG-DLM&_TB6

Question 11

Hypothesize how the combustion of large quantities of fossil fuels could affect the cycle shown below.Then explain how this could be further complicated by the global loss of vegetation,such as by the cutting of rain forests.

Accepted Answer

The formation of CO₂ from burning fossil

Question 12

Trace the path of each electron through the photosynthetic pathway,starting from H2O and proceeding to the cytochrome b6f complex.

Accepted Answer

See Figure 12.20 below.H₂O @#IMG-DLM&_T

Question 13

Transketolase requires the coenzyme

Accepted Answer

A)  cobalamin (vitamin B12). 
B)  pyridoxal phosphate. 
C)  tetrahydrofolic acid. 
D)  thiamine pyrophosphate. 
A)  cobalamin (vitamin B12). 
B)  pyridoxal phosphate. 
C)  tetrahydrofolic acid. 
D)  thiamine pyrophosphate.

Question 14

Heme and chlorophyll have similar overall structures.What is common between the two molecules?

Accepted Answer

A)  color 
B)  hydrophobic tail 
C)  polycyclic planar structure 
D)  metal ion found at their center 
A)  color 
B)  hydrophobic tail 
C)  polycyclic planar structure 
D)  metal ion found at their center

Question 15

Draw a picture of the chloroplast and show the location of and direction in which protons are pumped during photosynthetic light reactions.

Accepted Answer

See Figure 12.7 below.Protons

Question 16

What is the name of the plant leaf openings that open during the night and close during the day in CAM plants?

Accepted Answer

A)  mesophyll cells 
B)  stomata 
C)  guard cells 
D)  malate pore proteins 
A)  mesophyll cells 
B)  stomata 
C)  guard cells 
D)  malate pore proteins

Question 17

Ribulose bisphosphate carboxylase (rubisco)

Accepted Answer

A)  is the most abundant enzyme in the biosphere, comprising as much as 50% of plant cell protein. 
B)  catalyzes the reaction of C5 molecule and CO2 with a C6 sugar product. 
C)  is located in the thylakoid lumen. 
D)  requires NADPH and ATP to fix CO2. 
A)  is the most abundant enzyme in the biosphere, comprising as much as 50% of plant cell protein. 
B)  catalyzes the reaction of C5 molecule and CO2 with a C6 sugar product. 
C)  is located in the thylakoid lumen. 
D)  requires NADPH and ATP to fix CO2.

Question 18

Describe the arrangement of light-harvesting complexes relative to the reaction center in a plant's photosystem enzymes.

Accepted Answer

The reaction center is centrally located

Question 19

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 20

Which species from the light reactions keeps thioredoxin reduced so that it can activate enzymes in the Calvin cycle?

Accepted Answer

A)  ferredoxin 
B)  plastoquinone 
C)  P700 
D)  NADPH 
A)  ferredoxin 
B)  plastoquinone 
C)  P700 
D)  NADPH

Exam 12: Photosynthesis

Which is a characteristic of the second stage of the three-stage Calvin cycle?

The glyoxylate cycle reaction shown below is catalyzed by which enzyme class?

Under what condition(s)do the wasteful side reaction of O2 with rubisco become significant?

Approximately how many ATP are synthesized per O2 molecule generated in photosynthesis light reactions?

Chlorophyll absorbs

The five-step mechanism of ribulose bisphosphate carboxylase (rubisco)

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

Heme and chlorophyll have the same porphyrin cofactor,yet they have largely different roles.Compare their color and the metal ions employed by each.

What is the process depicted below,where plants react with O2?

Trace the electron from plastocyanin to NADPH in the photosynthetic electron transport system.

Hypothesize how the combustion of large quantities of fossil fuels could affect the cycle shown below.Then explain how this could be further complicated by the global loss of vegetation,such as by the cutting of rain forests.

Trace the path of each electron through the photosynthetic pathway,starting from H2O and proceeding to the cytochrome b6f complex.

Transketolase requires the coenzyme

Heme and chlorophyll have similar overall structures.What is common between the two molecules?

Draw a picture of the chloroplast and show the location of and direction in which protons are pumped during photosynthetic light reactions.

What is the name of the plant leaf openings that open during the night and close during the day in CAM plants?

Ribulose bisphosphate carboxylase (rubisco)

Describe the arrangement of light-harvesting complexes relative to the reaction center in a plant's photosystem enzymes.

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

Which species from the light reactions keeps thioredoxin reduced so that it can activate enzymes in the Calvin cycle?

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

Under what condition(s)do the wasteful side reaction of O₂ with rubisco become significant?

Approximately how many ATP are synthesized per O₂ molecule generated in photosynthesis light reactions?

What is the process depicted below,where plants react with O₂?

Trace the path of each electron through the photosynthetic pathway,starting from H₂O and proceeding to the cytochrome b₆f complex.