Question 1

The carbon assimilation ("dark") reactions of photosynthetic plants:

Accepted Answer

A)  are driven ultimately by the energy of sunlight. 
B)  are important to plants, but ultimately of little significance for bacteria and animals. 
C)  cannot occur in the light. 
D)  yield (reduced) NADH. 
E)  yield ATP, which is required for the light reactions. 
A)  are driven ultimately by the energy of sunlight. 
B)  are important to plants, but ultimately of little significance for bacteria and animals. 
C)  cannot occur in the light. 
D)  yield (reduced) NADH. 
E)  yield ATP, which is required for the light reactions.

Question 2

CAM plants, such as cactus and pineapple, are native to very hot and dry environments. Briefly describe the biochemical events that allow CAM plants to minimize water loss by closing their stroma during daylight hours.

Accepted Answer

CAM plants, such as cactus and pineapple

Question 3

Cyclic electron flow in chloroplasts produces:

Accepted Answer

A)  ATP and O2, but not NADPH. 
B)  ATP, but not NADPH or O2. 
C)  NADPH and ATP, but not O2. 
D)  NADPH, but not ATP or O2. 
E)  O2, but not ATP or NADPH. 
A)  ATP and O2, but not NADPH. 
B)  ATP, but not NADPH or O2. 
C)  NADPH and ATP, but not O2. 
D)  NADPH, but not ATP or O2. 
E)  O2, but not ATP or NADPH.

Question 4

Which statement is NOT true about plastids?

Accepted Answer

A)  Most of the proteins in a plastid are encoded in nuclear genes. 
B)  Plastids are encoded by a double membrane. 
C)  Plastids are self-replicating. 
D)  Plastids contain a small circular genome. 
E)  The inner membrane of plastids is permeable to polar and charged molecules. 
A)  Most of the proteins in a plastid are encoded in nuclear genes. 
B)  Plastids are encoded by a double membrane. 
C)  Plastids are self-replicating. 
D)  Plastids contain a small circular genome. 
E)  The inner membrane of plastids is permeable to polar and charged molecules.

Question 5

When glycerol is converted to glucose via gluconeogenesis in germinating seeds, the first glycolytic intermediate formed is:

Accepted Answer

A)  1,3-bisphosphoglycerate. 
B)  dihydroxyacetone phosphate. 
C)  glycerol 1,3-bisphosphate. 
D)  glycerol 3-phosphate. 
E)  ribulose 1,5-bisphosphate. 
A)  1,3-bisphosphoglycerate. 
B)  dihydroxyacetone phosphate. 
C)  glycerol 1,3-bisphosphate. 
D)  glycerol 3-phosphate. 
E)  ribulose 1,5-bisphosphate.

Question 6

Describe the interconversions between the triose-, pentose- and hexose-phosphate pools in the plant cell.

Accepted Answer

In plant cells, the interconversions bet

Question 7

Transketolase requires the coenzyme:

Accepted Answer

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

Question 8

During photophosphorylation in plants, electrons flow through a series of carriers in the chloroplast. What is the ultimate donor of electrons, and what is the ultimate acceptor? What provides the energy to move those electrons?

Accepted Answer

During photophosphorylation in plants, t

Question 9

Carbon dioxide has two important roles in the rubisco active site. What are these roles, and how do they differ from each other?

Accepted Answer

Carbon dioxide plays two important roles

Question 10

Describe what happens at photosystem I from the point where an antenna chlorophyll molecule absorbs a photon of light to the passage of an electron to NADP+.

Accepted Answer

When an antenna chlorophyll molecule abs

Question 11

The processes of oxidative phosphorylation coupled with electron transfer (in mitochondria) and photophosphorylation (in chloroplasts) resemble each other in certain respects. Describe five ways in which the two processes are similar, and describe three significant differences between the two processes.

Accepted Answer

Similarities between oxidative phosphory

Question 12

In the photolytic cleavage of water by the oxygen-evolving complex [2H2O $\rightarrow$ 4 H+ + 4e- + O2], how many photons of light at a wavelength of 680 nm are required?

Accepted Answer

A)  one 
B)  two 
C)  four 
D)  six 
E)  eight 
A)  one 
B)  two 
C)  four 
D)  six 
E)  eight

Question 13

Place the following electron-carriers into the CORRECT order as found in plant chloroplasts. 1) cytochrome b6f complex
2) P680
3) P700
4) plastocyanin
5) NADPH

Accepted Answer

A)  2, 1, 3, 4, 5 
B)  2, 4, 3, 1, 5 
C)  3, 1, 4, 2, 5 
D)  2, 1, 4, 3, 5 
E)  3, 4, 2, 1, 5 
A)  2, 1, 3, 4, 5 
B)  2, 4, 3, 1, 5 
C)  3, 1, 4, 2, 5 
D)  2, 1, 4, 3, 5 
E)  3, 4, 2, 1, 5

Question 14

Why is changing the wavelength of incident light to higher energy NOT as effective as changing the intensity of incident light with respect to photosynthesis?

Accepted Answer

Photosynthesis is the process by which g

Question 15

Reactions from which pathway are NOT specifically needed to synthesize carbohydrate from fatty acids in plants?

Accepted Answer

A)  gluconeogenesis 
B)  glyoxylate pathway 
C)  citric acid cycle 
D)  glycolate pathway 
E)  All of these pathways are necessary to synthesize carbohydrates from fatty acids. 
A)  gluconeogenesis 
B)  glyoxylate pathway 
C)  citric acid cycle 
D)  glycolate pathway 
E)  All of these pathways are necessary to synthesize carbohydrates from fatty acids.

Question 16

The assimilation of CO2 into organic compounds (triose phosphates) in green plants:

Accepted Answer

A)  involves condensation of the two-carbon compound acetate with CO2 to form 3-phosphoglycerate. 
B)  requires NADPH. 
C)  results in the production of ATP. 
D)  takes place at equal rates in light and darkness. 
E)  takes place in the cytosol. 
A)  involves condensation of the two-carbon compound acetate with CO2 to form 3-phosphoglycerate. 
B)  requires NADPH. 
C)  results in the production of ATP. 
D)  takes place at equal rates in light and darkness. 
E)  takes place in the cytosol.

Question 17

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. 
E)  CO2. 
A)  3-phosphoglycerate. 
B)  ATP. 
C)  ribulose 1,5-bisphosphate. 
D)  glyceraldehyde-3-phosphate. 
E)  CO2.

Question 18

Given that ~8 photons are required to produce one molecule of O2, roughly how many photons are required to produce one molecule of glucose.

Accepted Answer

The question seems to be referring to th

Question 19

Which of the reactions of the Calvin cycle is reversible?

Accepted Answer

A)  the conversion of fructose-1,6-bisphosphate to fructose-6-phosphate 
B)  the conversion of ribulose-5-phosphate to ribulose-1,5-bisphosphate 
C)  the conversion of ribose-5-phosphate to ribulose-5-phosphate 
D)  the conversion of sedoheptulose-1,7-bisphosphate into sedoheptulose-7-phosphate 
E)  None of these reactions is reversible. 
A)  the conversion of fructose-1,6-bisphosphate to fructose-6-phosphate 
B)  the conversion of ribulose-5-phosphate to ribulose-1,5-bisphosphate 
C)  the conversion of ribose-5-phosphate to ribulose-5-phosphate 
D)  the conversion of sedoheptulose-1,7-bisphosphate into sedoheptulose-7-phosphate 
E)  None of these reactions is reversible.

Question 20

Which statement is NOT true of the Pi-triose phosphate antiporter?

Accepted Answer

A)  The antiporter can move phosphate in or out of the chloroplast. 
B)  When Pi is moved into the chloroplast, it supports synthesis of ATP. 
C)  When triose phosphates are moved out of the chloroplast, they become incorporated into sucrose. 
D)  ATP and reducing equivalents are moved into the chloroplast by the antiporter. 
E)  The antiporter is found in the inner membrane of chloroplasts. 
A)  The antiporter can move phosphate in or out of the chloroplast. 
B)  When Pi is moved into the chloroplast, it supports synthesis of ATP. 
C)  When triose phosphates are moved out of the chloroplast, they become incorporated into sucrose. 
D)  ATP and reducing equivalents are moved into the chloroplast by the antiporter. 
E)  The antiporter is found in the inner membrane of chloroplasts.

Exam 20: Carbohydrate Biosynthesis in Plants and Bacteria

The carbon assimilation ("dark") reactions of photosynthetic plants:

CAM plants, such as cactus and pineapple, are native to very hot and dry environments. Briefly describe the biochemical events that allow CAM plants to minimize water loss by closing their stroma during daylight hours.

Cyclic electron flow in chloroplasts produces:

Which statement is NOT true about plastids?

When glycerol is converted to glucose via gluconeogenesis in germinating seeds, the first glycolytic intermediate formed is:

Describe the interconversions between the triose-, pentose- and hexose-phosphate pools in the plant cell.

Transketolase requires the coenzyme:

During photophosphorylation in plants, electrons flow through a series of carriers in the chloroplast. What is the ultimate donor of electrons, and what is the ultimate acceptor? What provides the energy to move those electrons?

Carbon dioxide has two important roles in the rubisco active site. What are these roles, and how do they differ from each other?

Describe what happens at photosystem I from the point where an antenna chlorophyll molecule absorbs a photon of light to the passage of an electron to NADP+.

In the photolytic cleavage of water by the oxygen-evolving complex [2H2O →\rightarrow→ 4 H+ + 4e- + O2], how many photons of light at a wavelength of 680 nm are required?

Place the following electron-carriers into the CORRECT order as found in plant chloroplasts. 1) cytochrome b6f complex 2) P680 3) P700 4) plastocyanin 5) NADPH

Why is changing the wavelength of incident light to higher energy NOT as effective as changing the intensity of incident light with respect to photosynthesis?

Reactions from which pathway are NOT specifically needed to synthesize carbohydrate from fatty acids in plants?

The assimilation of CO2 into organic compounds (triose phosphates) in green plants:

The final product that is formed by the enzyme rubisco is:

Given that ~8 photons are required to produce one molecule of O2, roughly how many photons are required to produce one molecule of glucose.

Which of the reactions of the Calvin cycle is reversible?

Which statement is NOT true of the Pi-triose phosphate antiporter?

The Foundations of Biochemistry

Water

Amino Acids, Peptides, and Proteins

The Three-Dimensional Structure of Proteins

Protein Function

Enzymes

Carbohydrates and Glycobiology

Nucleotides and Nucleic Acids

DNA-Based Information Technologies

Lipids

Biological Membranes and Transport

Biosignaling

Bioenergetics and Biochemical Reaction Types

Glycolysis, Gluconeogenesis, and the Pentose Phosphate Pathway

Principles of Metabolic Regulation

The Citric Acid Cycle

Fatty Acid Catabolism

Amino Acid Oxidation and the Production of Urea

Oxidative Phosphorylation and Photophosphorylation

Lipid Biosynthesis

Biosynthesis of Amino Acids, Nucleotides, and Related Molecules

Hormonal Regulation and Integration of Mammalian Metabolism

Genes and Chromosomes

DNA Metabolism

RNA Metabolism

Protein Metabolism

Regulation of Gene Expression

Filters

Describe what happens at photosystem I from the point where an antenna chlorophyll molecule absorbs a photon of light to the passage of an electron to NADP⁺.

In the photolytic cleavage of water by the oxygen-evolving complex [2H₂O $\rightarrow$ 4 H⁺ + 4e^- + O₂], how many photons of light at a wavelength of 680 nm are required?

Place the following electron-carriers into the CORRECT order as found in plant chloroplasts. 1) cytochrome b₆f complex 2) P680 3) P700 4) plastocyanin 5) NADPH

The assimilation of CO₂ into organic compounds (triose phosphates) in green plants:

Given that ~8 photons are required to produce one molecule of O₂, roughly how many photons are required to produce one molecule of glucose.

Which statement is NOT true of the P_i-triose phosphate antiporter?