Question 1

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 2

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

Question 3

For every 12 molecules of 3-phosphoglycerate produced by rubisco, _____ are converted to hexoses while _____ are recycled to ribulose-1,5-bisphosphate.

Accepted Answer

A) 2; 10 
B) 4; 8 
C) 6; 6 
D) 8; 4 
E) 10; 2 
A) 2; 10 
B) 4; 8 
C) 6; 6 
D) 8; 4 
E) 10; 2 A

Question 4

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 $\rarr$ Q $\rarr$ cytochrome b6f complex $\rarr$PC $\rarr$ PSII $\rarr$0 Fd $\rarr$NADP+ 
B) PSI $\rarr$ cytochrome b6f complex $\rarr$ Q $\rarr$ PC $\rarr$ PSII $\rarr$ Fd $\rarr$NADP+ 
C) PSII $\rarr$ Q $\rarr$ cytochrome b6f complex $\rarr$ PC $\rarr$ PSI $\rarr$ Fd $\rarr$NADP+ 
D) PSII $\rarr$ PC $\rarr$ Q $\rarr$ Fd $\rarr$ PSI $\rarr$ cytochrome b6f complex $\rarr$ NADP+ 
E) PSII $\rarr$ Fd $\rarr$ PC $\rarr$cytochrome b6f complex $\rarr$ PSI $\rarr$Q $\rarr$NADP+ 
A) PSI $\rarr$ Q $\rarr$ cytochrome b6f complex $\rarr$PC $\rarr$ PSII $\rarr$0 Fd $\rarr$NADP+ 
B) PSI $\rarr$ cytochrome b6f complex $\rarr$ Q $\rarr$ PC $\rarr$ PSII $\rarr$ Fd $\rarr$NADP+ 
C) PSII $\rarr$ Q $\rarr$ cytochrome b6f complex $\rarr$ PC $\rarr$ PSI $\rarr$ Fd $\rarr$NADP+ 
D) PSII $\rarr$ PC $\rarr$ Q $\rarr$ Fd $\rarr$ PSI $\rarr$ cytochrome b6f complex $\rarr$ NADP+ 
E) PSII $\rarr$ Fd $\rarr$ PC $\rarr$cytochrome b6f complex $\rarr$ PSI $\rarr$Q $\rarr$NADP+

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-$\beta$-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 
A) neutralizes negative charges of active site Asp and Glu, enabling ionization of CO2 
B) activates water molecule that hydrates the carboxy-$\beta$-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

Question 6

Which of the following shows the overall equation for the light reactions?

Accepted Answer

A) 2 H2O + 1 NADP+ $\rarr$ 1 H+ + O2 + 1 NADPH, requires 4 photons 
B) 2 H2O + 1 NADP+ $\rarr$ 1 H+ + O2 + 1 NADPH, requires 8 photons 
C) 2 H2O + 2 NADP+ $\rarr$ 2 H+ + O2 + 2 NADPH, requires 4 photons 
D) 2 H2O + 2 NADP+ $\rarr$ 2 H+ + O2 + 2 NADPH, requires 8 photons 
E) 2 H2O + 2 NADP+ $\rarr$ 2 H+ + O2 + 2 NADPH, requires 16 photons 
A) 2 H2O + 1 NADP+ $\rarr$ 1 H+ + O2 + 1 NADPH, requires 4 photons 
B) 2 H2O + 1 NADP+ $\rarr$ 1 H+ + O2 + 1 NADPH, requires 8 photons 
C) 2 H2O + 2 NADP+ $\rarr$ 2 H+ + O2 + 2 NADPH, requires 4 photons 
D) 2 H2O + 2 NADP+ $\rarr$ 2 H+ + O2 + 2 NADPH, requires 8 photons 
E) 2 H2O + 2 NADP+ $\rarr$ 2 H+ + O2 + 2 NADPH, requires 16 photons

Question 7

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

Question 8

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 above 
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 above

Question 9

For each molecule of CO2 fixed by the Calvin cycle, how many ATP and NADPH are required?

Accepted Answer

A) 3 ATP, 1 NADPH 
B) 3 ATP, 2 NADPH 
C) 6 ATP, 2 NADPH 
D) 6 ATP, 3 NADPH 
E) none of the above 
A) 3 ATP, 1 NADPH 
B) 3 ATP, 2 NADPH 
C) 6 ATP, 2 NADPH 
D) 6 ATP, 3 NADPH 
E) none of the above

Question 10

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+ 
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+

Question 11

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 infrared 
A) UV only 
B) visible only 
C) infrared only 
D) UV and visible 
E) visible and infrared

Question 12

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) fructose 
A) amylose 
B) amylopectin 
C) glucose 
D) sucrose 
E) fructose

Question 13

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+ $\rarr$ 2 H+ + O2 + 2 NADPH  E$\circ$' = -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 k

Question 14

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$\rarr$ ADP + Pi 
D) ATP $\rarr$ AMP + PPi 
E) none of the above 
A) NADH 
B) NADPH 
C) ATP$\rarr$ ADP + Pi 
D) ATP $\rarr$ AMP + PPi 
E) none of the above

Question 15

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

Question 16

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 above 
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 above

Question 17

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

Question 18

Under what conditions does the cyclic electron flow of photosystem I occur?

Accepted Answer

A) high NADPH, low ATP 
B) low NADPH, high ATP 
C) low NADPH, low ATP 
D) high NADPH, high ATP 
E) under conditions when light is not intense enough to excite PSII 
A) high NADPH, low ATP 
B) low NADPH, high ATP 
C) low NADPH, low ATP 
D) high NADPH, high ATP 
E) under conditions when light is not intense enough to excite PSII

Question 19

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) $\beta$-carotene 
D) phycocyanin 
E) none of the above 
A) chlorophyll a 
B) chlorophyll b 
C) $\beta$-carotene 
D) phycocyanin 
E) none of the above

Question 20

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) 16 
A) 1 
B) 2 
C) 4 
D) 8 
E) 16

Exam 16: Photosynthesis

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

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

For every 12 molecules of 3-phosphoglycerate produced by rubisco, _____ are converted to hexoses while _____ are recycled to ribulose-1,5-bisphosphate.

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

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

Which of the following shows the overall equation for the light reactions?

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

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

For each molecule of CO2 fixed by the Calvin cycle, how many ATP and NADPH are required?

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

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

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

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

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?

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?

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

Under what conditions does the cyclic electron flow of photosystem I occur?

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

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

The Scope of Biochemistry

The Matrix of Life: Weak Interactions in an Aqueous Environment

The Energetics of Life

Nucleic Acids

Introduction to Proteins: the Primary Level of Protein Structure

The Three-Dimensional Structure of Proteins

Protein Function and Evolution

Contractile Proteins and Molecular Motors

Carbohydrates: Sugars, Saccharides, Glycans

Lipids, Membranes and Cellular Transport

Enzymes: Biological Catalysts

Chemical Logic of Metabolism

Carbohydrate Metabolism: Glycolysis, Gluconeogenesis, Glycogen Metabolism, and the Pentose Phosphate Pathway

Citric Acid Cycle and Glyoxylate Cycle

Electron Transport, Oxidative Phosphorylation, and Oxygen Metabolism

Lipid Metabolism I: Fatty Acids, Triacylglycerols, and Lipoproteins

Interorgan and Intracellular Coordination of Energy Metabolism in Vertebrates

Lipid Metabolism Ii: Membrane Lipids, Steroids, Isoprenoids, and Eicosanoids

Metabolism of Nitrogenous Compounds I: Principles of Biosynthesis, Utilization, and Turnover

Metabolism of Nitogenous Compounds II: Amino Acids, Porphyrins, and Neurotransmitters

Nucleotide Metabolism

Mechanisms of Signal Transduction

Genes, Genomes and Chromosomes

DNA Replication

DNA Restructuring: Repair, Recombination, Rearrangement, Amplification

Information Readout: Transcription and Post-Transcriptional Processing

Information Decoding: Translation and Post-Translational Protein Processing

Regulation of Gene Expression

Filters

For every 12 molecules of 3-phosphoglycerate produced by rubisco, _ are converted to hexoses while _ are recycled to ribulose-1,5-bisphosphate.

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

For each molecule of CO₂ fixed by the Calvin cycle, how many ATP and NADPH are required?