Question 1

What is the main advantage for plants that use the C₄ pathway in addition to the Calvin cycle for the fixation of carbon dioxide?

Accepted Answer

A) Fewer ATP are consumed to produce carbohydrates using the C₄ pathway as opposed to the Calvin cycle. 
B) The C₄ pathway allows for fixation of carbon dioxide at night. 
C) The C₄ pathway aids in the avoidance of the oxygenation of ribulose 1,5-bisphosphate. 
D) The C₄ cycle allows photosynthesis to occur at a wide range of wavelengths of light. 
A) Fewer ATP are consumed to produce carbohydrates using the C₄ pathway as opposed to the Calvin cycle. 
B) The C₄ pathway allows for fixation of carbon dioxide at night. 
C) The C₄ pathway aids in the avoidance of the oxygenation of ribulose 1,5-bisphosphate. 
D) The C₄ cycle allows photosynthesis to occur at a wide range of wavelengths of light. C

Question 2

Photosystems I and II are located in the same region of the chloroplast structure,since both contain chlorophyll.

Accepted Answer

A) True 
 B)False  False

Question 3

In the Z scheme describing electron flow in photosynthesis,the electron donor to P680 is ________,while the electron donor to P700 is ________.

Accepted Answer

A) H2O;plastocyanin 
B) plastocyanin;H₂O 
C) O2;plastocyanin 
D) plastocyanin;O2 
E) O2;H₂O 
A) H2O;plastocyanin 
B) plastocyanin;H₂O 
C) O2;plastocyanin 
D) plastocyanin;O2 
E) O2;H₂O A

Question 4

The initial reactions of the C₄ pathway occur in the ________.

Accepted Answer

A) chloroplast stroma 
B) mesophyll cells 
C) bundle sheath cell cytosol 
D) stomata plasma membrane 
A) chloroplast stroma 
B) mesophyll cells 
C) bundle sheath cell cytosol 
D) stomata plasma membrane

Question 5

Which is not required to activate rubisco?

Accepted Answer

A) CO2. 
B) Mg²+. 
C) Light. 
D) NADP+. 
E) All of the above are required. 
A) CO2. 
B) Mg²+. 
C) Light. 
D) NADP+. 
E) All of the above are required.

Question 6

Which statement is false about the photosynthesis in plants?

Accepted Answer

A) PSI reduces ferredoxin. 
B) PSI produces ferredoxin. 
C) ATP is synthesized in the lumen. 
D) PQH2 can diffuse within the thylakoid membrane. 
A) PSI reduces ferredoxin. 
B) PSI produces ferredoxin. 
C) ATP is synthesized in the lumen. 
D) PQH2 can diffuse within the thylakoid membrane.

Question 7

Which statement is false about C₄ plants?

Accepted Answer

A) They tend to grow at high temperatures and high light intensities. 
B) They decrease the ratio of CO2 to O2 in cells where Rubisco is active. 
C) Corn is an example of a C₄ plant. 
D) They avoid wasteful photorespiration by means of secondary pathways for carbon dioxide fixation. 
A) They tend to grow at high temperatures and high light intensities. 
B) They decrease the ratio of CO2 to O2 in cells where Rubisco is active. 
C) Corn is an example of a C₄ plant. 
D) They avoid wasteful photorespiration by means of secondary pathways for carbon dioxide fixation.

Question 8

The photosynthetic dark reactions ________.

Accepted Answer

A) occur only in the dark (nocturnal) 
B) are the main source of ATP in photosynthesis 
C) convert carbon dioxide to carbohydrates 
D) produce the reduced coenzyme NADH 
A) occur only in the dark (nocturnal) 
B) are the main source of ATP in photosynthesis 
C) convert carbon dioxide to carbohydrates 
D) produce the reduced coenzyme NADH

Question 9

The source of electrons for green sulfur bacteria is ________,and the source of electrons for cyanobacteria is ________.

Accepted Answer

A) NADPH;NAD+ 
B) H₂S;H₂O 
C) H₂O;H₂S 
D) cytochrome c;cytochrome bf 
A) NADPH;NAD+ 
B) H₂S;H₂O 
C) H₂O;H₂S 
D) cytochrome c;cytochrome bf

Question 10

The cytochrome bf complex connects the electron flow from photosystem I (PSI)to photosystem II (PSII)according to the Z scheme describing electron flow in photosynthesis.

Accepted Answer

A) True 
 B)False

Question 11

Reactions to extract electrons from water require ________ to reverse electron flow.

Accepted Answer

A) powerful oxidizing agents 
B) powerful reducing agents 
C) dark reactions 
D) ATP 
A) powerful oxidizing agents 
B) powerful reducing agents 
C) dark reactions 
D) ATP

Question 12

The reactions that allow plants such as cacti and orchids to assimilate carbon at night are referred to as ________.

Accepted Answer

A) the Calvin cycle 
B) nocturnal photorespiration 
C) the C₄ pathway 
D) Crassulacean acid metabolism 
A) the Calvin cycle 
B) nocturnal photorespiration 
C) the C₄ pathway 
D) Crassulacean acid metabolism

Question 13

The site of light-dependent reactions in the chloroplast is

Accepted Answer

A) the stroma. 
B) the thylakoids. 
C) the outer membrane. 
D) the lumen. 
E) All of the above. 
A) the stroma. 
B) the thylakoids. 
C) the outer membrane. 
D) the lumen. 
E) All of the above.

Question 14

Plant pigments which can absorb light include

Accepted Answer

A) chlorophyll a. 
B) chlorophyll b. 
C) carotenoids and phycobilins. 
D) All of the above. 
E) A and B only. 
A) chlorophyll a. 
B) chlorophyll b. 
C) carotenoids and phycobilins. 
D) All of the above. 
E) A and B only.

Question 15

Which molecule is the CO2 acceptor in the first step of the Calvin cycle?

Accepted Answer

A) Rubisco. 
B) Ribulose 1,5-bisphosphate. 
C) 3-phosphoglycerate. 
D) Glyceraldehyde-3-phosphate. 
A) Rubisco. 
B) Ribulose 1,5-bisphosphate. 
C) 3-phosphoglycerate. 
D) Glyceraldehyde-3-phosphate.

Question 16

Photosynthesis in PS II is cyclic,since there is no net gain or loss of electrons and no requirement for an outside source of electrons.

Accepted Answer

A) True 
 B)False

Question 17

All photosynthetic bacteria give off O2 as an end-product of photosynthesis.

Accepted Answer

A) True 
 B)False

Question 18

Which statement is false about bacteriorhodopsin?

Accepted Answer

A) It occurs in archaebacteria. 
B) A molecule of retinal inside bacteriorhodopsin converts from the trans to the cis configuration when light is absorbed. 
C) It creates a light-induced proton gradient across a membrane. 
D) Its activity is coupled to PSI and PSII. 
A) It occurs in archaebacteria. 
B) A molecule of retinal inside bacteriorhodopsin converts from the trans to the cis configuration when light is absorbed. 
C) It creates a light-induced proton gradient across a membrane. 
D) Its activity is coupled to PSI and PSII.

Question 19

Both the C₄ and CAM carbon-assimilation pathways use bicarbonate ions to convert phosphoenolpyruvate to oxaloacetate.

Accepted Answer

A) True 
 B)False

Question 20

Solar energy is captured in chemical form as ATP and NADPH by the process of photosynthesis.

Accepted Answer

A) True 
 B)False

Exam 15: Photosynthesis

What is the main advantage for plants that use the C₄ pathway in addition to the Calvin cycle for the fixation of carbon dioxide?

Photosystems I and II are located in the same region of the chloroplast structure,since both contain chlorophyll.

In the Z scheme describing electron flow in photosynthesis,the electron donor to P680 is ________,while the electron donor to P700 is ________.

The initial reactions of the C₄ pathway occur in the ________.

Which is not required to activate rubisco?

Which statement is false about the photosynthesis in plants?

Which statement is false about C₄ plants?

The photosynthetic dark reactions ________.

The source of electrons for green sulfur bacteria is ________,and the source of electrons for cyanobacteria is ________.

The cytochrome bf complex connects the electron flow from photosystem I (PSI)to photosystem II (PSII)according to the Z scheme describing electron flow in photosynthesis.

Reactions to extract electrons from water require ________ to reverse electron flow.

The reactions that allow plants such as cacti and orchids to assimilate carbon at night are referred to as ________.

The site of light-dependent reactions in the chloroplast is

Plant pigments which can absorb light include

Which molecule is the CO2 acceptor in the first step of the Calvin cycle?

Photosynthesis in PS II is cyclic,since there is no net gain or loss of electrons and no requirement for an outside source of electrons.

All photosynthetic bacteria give off O2 as an end-product of photosynthesis.

Which statement is false about bacteriorhodopsin?

Both the C₄ and CAM carbon-assimilation pathways use bicarbonate ions to convert phosphoenolpyruvate to oxaloacetate.

Solar energy is captured in chemical form as ATP and NADPH by the process of photosynthesis.

Introduction to Biochemistry

Water

Amino Acids and the Primary Structures of Proteins

Proteins: Three-Dimensional Structure and Function

Properties of Enzymes

Mechanisms of Enzymes

Coenzymes and Vitamins

Carbohydrates

Lipids and Membranes

Introduction to Metabolism

Glycolysis

Gluconeogenesis, the Pentose Phosphate Pathway, and Glycogen Metabolism

The Citric Acid Cycle

Electron Transport and Atp Synthesis

Lipid Metabolism

Amino Acid Metabolism

Nucleotide Metabolism

Nucleic Acids

DNA Replication, repair, and Recombination

Transcription and RNA Processing

Protein Synthesis

Filters

In the Z scheme describing electron flow in photosynthesis,the electron donor to P680 is ,while the electron donor to P700 is .

The source of electrons for green sulfur bacteria is ,and the source of electrons for cyanobacteria is .

Which molecule is the CO₂ acceptor in the first step of the Calvin cycle?

All photosynthetic bacteria give off O₂ as an end-product of photosynthesis.