Question 1

Which of the following correctly identifies the proton pumping in the two-photosystem light reactions?

Accepted Answer

A)  PSII: 4 protons;cytochrome b6f complex: 8 protons
B)  cytochrome b6f complex: 8 protons;PSI: 4 protons
C)  PSII: 4 protons;ferredoxin-NADP+ oxidoreductase: 4 protons
D)  PSII: 4 protons;PSI: 4 protons;ferredoxin-NADP+ oxidoreductase: 4 protons
E)  none of the aboveF) B) and C)
G) A) and E) A

Question 2

Which of the following would have an inhibitory effect upon rubisco?

Accepted Answer

A)  Mg2+
B)  CO2
C)  H+
D)  reduced thioredoxin
E)  none of the aboveF) B) and C)
G) D) and E)

Question 3

If light with an average wavelength of 660 nm is used to power the light reactions of  photosynthesis,what is the efficiency in terms of energy captured as NADPH and ATP based upon the following information?

2 H2O + 2 NADP+ $\to$ 2 H+ + O2 + 2 NADPH ES1U1P1$\circ$S1S1P0' = -0.50 V
the oxidation of 2 water molecules with production of 2 NADPH requires 8 photons
12 protons are transported to the thylakoid lumen for each oxygen produced

Accepted Answer

Energy of 2 NADPH production: (4)(96.5 kJ/V$\bullet$mol)(-0.50 V)= 193 kJ/2 NADPH

Energy of ATP production: 12 protons (1 ATP/3 protons)= 4 ATP
4 ATP (~50 kJ/mol)= 200 kJ/mol

Total energy required = 193 kJ + 200 kJ = 393 kJ

Energy of 8 einsteins of 660 nm light and calculation of efficiency:

Question 4

Which of the following explains why an electron will eventually travel to a chlorophyll molecule in the reaction center as opposed to just "wandering around" all of the antenna molecules?

Accepted Answer

A)  antenna chlorophyll molecules are associated with proteins and have a higher excited state energy level
B)  antenna chlorophyll molecules are associated with proteins and have a lower excited state energy level
C)  reaction center chlorophyll molecules are associated with proteins and have a higher excited state energy level
D)  reaction center chlorophyll molecules are associated with proteins and have a lower excited state energy level
E)  none of the aboveF) B) and D)
G) C) and E)

Question 5

In the mechanism of Rubisco,what role does the Mg2+ play?

Accepted Answer

A)  neutralizes negative charges of active site Asp and Glu,enabling ionization of CO2
B)  activates water molecule that hydrates the carboxy- β\betaβ -keto intermediate
C)  complexes with the phosphate on C-1 to hold ribulose-1,5-bisphosphate in the active site
D)  repels the product,3-phosphoglycerate,allowing it to leave the active site more rapidly
E)  none of the above F) None of the above
G) A) and B)

Question 6

Which of the following best describes photosynthesis in purple photosynthetic bacteria?

Accepted Answer

A)  a reaction center resembling PSI transfers electrons to plastocyanin
B)  a reaction center resembling PSII transfers electrons to plastoquinone
C)  water is split by the reaction center that resembles PSII
D)  NADPH is generated using electrons from a protein resembling ferredoxin
E)  the proton gradient is used for both ATP synthesis and NADPH generationF) C) and D)
G) B) and C)

Question 7

Which of the following describes the oxidation reactions for the two manganese ions that undergo oxidation in the oxygen-evolving complex?

Accepted Answer

A)  a Mn2+ is oxidized to a Mn4+ and a Mn3+ is oxidized to a Mn5+
B)  a Mn2+ is oxidized to a Mn5+ and a Mn3+ is oxidized to a Mn4+
C)  a Mn2+ is oxidized to a Mn5+ and a Mn2+ is oxidized to a Mn3+
D)  a Mn2+ is oxidized to a Mn5+ and a Mn4+ is oxidized to a Mn5+
E)  two Mn2+ are oxidized to Mn4+F) B) and C)
G) C) and E)

Question 8

What specific part of the chloroplast is responsible for the light reactions of photosynthesis?

Accepted Answer

A)  thylakoid lumen
B)  thylakoid membrane
C)  stroma
D)  inner membrane of chloroplast
E)  outer membrane of chloroplastF) A) and E)
G) B) and D)

Question 9

What is the minimum number of photons that must be absorbed by PSII to reduce two molecules of water to one molecule of oxygen?

Accepted Answer

A)  1
B)  2
C)  4
D)  8
E)  16F) A) and B)
G) A) and C)

Question 10

What range type(s) of electromagnetic radiation are absorbed by photosynthetic pigments to allow the reactions of photosynthesis to occur?

Accepted Answer

A)  UV only
B)  visible only
C)  infrared only
D)  UV and visible
E)  visible and infraredF) None of the above
G) B) and E)

Question 11

The energy available from the protonmotive force across the thylakoid membrane is about 20 kJ/mol of protons.How much energy per mole of photons absorbed by the two photosystems does this equal?

Accepted Answer

A)  13 kJ/mol
B)  30 kJ/mol
C)  40 kJ/mol
D)  60 kJ/mol
E)  none of the aboveF) A) and B)
G) C) and D)

Question 12

Which of the following acts as a corepressor for the transcription of chloroplast genes?

Accepted Answer

A)  3-phosphoglycerate
B)  fructose-1,6-bisphosphate
C)  CO2
D)  sucrose
E)  none of the aboveF) B) and D)
G) C) and D)

Question 13

If the following 14C labeled molecules served as substrates for rubisco (the labeled carbons are indicated with *),where would the 14C labels end up in the immediate product(s)of the reaction? Draw the product(s),clearly showing which atom(s)would be labeled.

Accepted Answer

Question 14

Which of the following photosynthetic pigments would give rise to the yellow or red color of leaves seen during autumn?

Accepted Answer

A)  chlorophyll a
B)  chlorophyll b
C)   β\betaβ -carotene
D)  phycocyanin
E)  none of the above F) A) and D)
G) A) and E) C

Question 15

Which of the following depicts the general flow of electrons in the two-photosystem light reactions? (Q = plastoquinone,PC = plastocyanin,Fd = ferredoxin

Accepted Answer

A)  PSI  →	o→  Q  →	o→  cytochrome b6f complex  →	o→  PC  →	o→  PSII  →	o→  Fd  →	o→  NADP+
B)  PSI  →	o→  cytochrome b6f complex  →	o→  Q  →	o→  PC  →	o→  PSII  →	o→  Fd  →	o→  NADP+
C)  PSII  →	o→  Q  →	o→  cytochrome b6f complex  →	o→  PC  →	o→  PSI  →	o→  Fd  →	o→  NADP+
D)  PSII  →	o→  PC  →	o→  Q  →	o→  Fd  →	o→  PSI  →	o→  cytochrome b6f complex  →	o→  NADP+
E)  PSII  →	o→  Fd  →	o→  PC  →	o→  cytochrome b6f complex  →	o→  PSI  →	o→  Q  →	o→  NADP+ F) A) and B)
G) C) and D)

Question 16

When photorespiration occurs and phosphoglycolate must be salvaged,which of the following occurs during the salvage reactions?

Accepted Answer

A)  NADP+ is used in the oxidation of glycolate to glyoxylate
B)  NADPH is used in the reduction of hydroxypyruvate to glycerate
C)  carbon is lost in the form of CO2
D)  ATP is made during the conversion of phosphoglycolate to glycolate
E)  none of the aboveF) C) and E)
G) B) and C)

Question 17

Which of the following carbohydrates is the most common molecule exported by photosynthetic cells for use in other parts of the plant?

Accepted Answer

A)  amylose
B)  amylopectin
C)  glucose
D)  sucrose
E)  fructoseF) A) and E)
G) C) and D)

Question 18

Reaction of ribulose-1,5-bisphosphate with oxygen and then water results in the following intermediate.Show the resulting products from this reaction:

Accepted Answer

The answer of Reaction of ribulose-1,5-bisphosphate with oxygen and then...

Question 19

Which of the following is required for the reaction catalyzed by rubisco in order to drive the reaction to completion?

Accepted Answer

A)  NADH
B)  NADPH
C)  ATP  →	o→  ADP + Pi
D)  ATP  →	o→  AMP + PPi
E)  none of the above F) A) and E)
G) B) and C)

Question 20

The following reaction would be catalyzed by which of the following enzymes?

Accepted Answer

A)  ribulose-5-phosphate epimerase
B)  transaldolase
C)  transketolase
D)  triose phosphate isomerase
E)  pentose phosphate transferaseF) A) and E)
G) A) and D)

Exam 16: Photosynthesis

Which of the following correctly identifies the proton pumping in the two-photosystem light reactions?

Correct Answer
verified
A

Which of the following would have an inhibitory effect upon rubisco?

Correct Answer
verified

Which of the following explains why an electron will eventually travel to a chlorophyll molecule in the reaction center as opposed to just "wandering around" all of the antenna molecules?

Correct Answer
verified

In the mechanism of Rubisco,what role does the Mg²⁺ play?

Correct Answer
verified

Which of the following best describes photosynthesis in purple photosynthetic bacteria?

Correct Answer
verified

Which of the following describes the oxidation reactions for the two manganese ions that undergo oxidation in the oxygen-evolving complex?

Correct Answer
verified

What specific part of the chloroplast is responsible for the light reactions of photosynthesis?

Correct Answer
verified

What is the minimum number of photons that must be absorbed by PSII to reduce two molecules of water to one molecule of oxygen?

Correct Answer
verified

What range type(s) of electromagnetic radiation are absorbed by photosynthetic pigments to allow the reactions of photosynthesis to occur?

Correct Answer
verified

The energy available from the protonmotive force across the thylakoid membrane is about 20 kJ/mol of protons.How much energy per mole of photons absorbed by the two photosystems does this equal?

Correct Answer
verified

Which of the following acts as a corepressor for the transcription of chloroplast genes?

Correct Answer
verified

If the following ¹⁴C labeled molecules served as substrates for rubisco (the labeled carbons are indicated with *),where would the ¹⁴C labels end up in the immediate product(s)of the reaction? Draw the product(s),clearly showing which atom(s)would be labeled.

Correct Answer
verified

Which of the following photosynthetic pigments would give rise to the yellow or red color of leaves seen during autumn?

Correct Answer
verified
C

Which of the following depicts the general flow of electrons in the two-photosystem light reactions? (Q = plastoquinone,PC = plastocyanin,Fd = ferredoxin

Correct Answer
verified

When photorespiration occurs and phosphoglycolate must be salvaged,which of the following occurs during the salvage reactions?

Correct Answer
verified

Which of the following carbohydrates is the most common molecule exported by photosynthetic cells for use in other parts of the plant?

Correct Answer
verified

Reaction of ribulose-1,5-bisphosphate with oxygen and then water results in the following intermediate.Show the resulting products from this reaction:

Correct Answer
verified

Which of the following is required for the reaction catalyzed by rubisco in order to drive the reaction to completion?

Correct Answer
verified

The following reaction would be catalyzed by which of the following enzymes?

Correct Answer
verified

Exam 16: Photosynthesis

Which of the following correctly identifies the proton pumping in the two-photosystem light reactions?

Correct AnswerverifiedA

Which of the following would have an inhibitory effect upon rubisco?

Correct AnswerverifiedShow Answer

Which of the following explains why an electron will eventually travel to a chlorophyll molecule in the reaction center as opposed to just "wandering around" all of the antenna molecules?

Correct AnswerverifiedShow Answer

In the mechanism of Rubisco,what role does the Mg2+ play?

Correct AnswerverifiedShow Answer

Which of the following best describes photosynthesis in purple photosynthetic bacteria?

Correct AnswerverifiedShow Answer

Which of the following describes the oxidation reactions for the two manganese ions that undergo oxidation in the oxygen-evolving complex?

Correct AnswerverifiedShow Answer

What specific part of the chloroplast is responsible for the light reactions of photosynthesis?

Correct AnswerverifiedShow Answer

What is the minimum number of photons that must be absorbed by PSII to reduce two molecules of water to one molecule of oxygen?

Correct AnswerverifiedShow Answer

What range type(s) of electromagnetic radiation are absorbed by photosynthetic pigments to allow the reactions of photosynthesis to occur?

Correct AnswerverifiedShow Answer

The energy available from the protonmotive force across the thylakoid membrane is about 20 kJ/mol of protons.How much energy per mole of photons absorbed by the two photosystems does this equal?

Correct AnswerverifiedShow Answer

Which of the following acts as a corepressor for the transcription of chloroplast genes?

Correct AnswerverifiedShow Answer

If the following 14C labeled molecules served as substrates for rubisco (the labeled carbons are indicated with *),where would the 14C labels end up in the immediate product(s)of the reaction? Draw the product(s),clearly showing which atom(s)would be labeled.

Correct AnswerverifiedShow Answer

Which of the following photosynthetic pigments would give rise to the yellow or red color of leaves seen during autumn?

Correct AnswerverifiedC

Which of the following depicts the general flow of electrons in the two-photosystem light reactions? (Q = plastoquinone,PC = plastocyanin,Fd = ferredoxin

Correct AnswerverifiedShow Answer

When photorespiration occurs and phosphoglycolate must be salvaged,which of the following occurs during the salvage reactions?

Correct AnswerverifiedShow Answer

Which of the following carbohydrates is the most common molecule exported by photosynthetic cells for use in other parts of the plant?

Correct AnswerverifiedShow Answer

Reaction of ribulose-1,5-bisphosphate with oxygen and then water results in the following intermediate.Show the resulting products from this reaction:

Correct AnswerverifiedShow Answer

Which of the following is required for the reaction catalyzed by rubisco in order to drive the reaction to completion?

Correct AnswerverifiedShow Answer

The following reaction would be catalyzed by which of the following enzymes?

Correct AnswerverifiedShow Answer

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A

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In the mechanism of Rubisco,what role does the Mg²⁺ play?

Correct Answer
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If the following ¹⁴C labeled molecules served as substrates for rubisco (the labeled carbons are indicated with *),where would the ¹⁴C labels end up in the immediate product(s)of the reaction? Draw the product(s),clearly showing which atom(s)would be labeled.

Correct Answer
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C

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