Question 1

When transketolase acts on fructose 6-phosphate and glyceraldehyde 3-phosphate, the products are:

Accepted Answer

A)  3-phosphoglycerate and glyceraldehyde 3-phosphate. 
B)  3-phosphoglycerate and two molecules of glyceraldehyde 3-phosphate. 
C)  dihydroxyacetone phosphate and glucose 6-phosphate. 
D)  xylulose 5-phosphate and erythrose 4-phosphate. 
E)  xylulose 5-phosphate and ribose 5-phosphate. 
A)  3-phosphoglycerate and glyceraldehyde 3-phosphate. 
B)  3-phosphoglycerate and two molecules of glyceraldehyde 3-phosphate. 
C)  dihydroxyacetone phosphate and glucose 6-phosphate. 
D)  xylulose 5-phosphate and erythrose 4-phosphate. 
E)  xylulose 5-phosphate and ribose 5-phosphate.

Question 2

Some photosynthetic bacteria contain the protein bacteriorhodopsin, which absorbs light and pumps protons out of the cell directly. Briefly describe how such a cell could use bacteriorhodopsin and an H+ATPase to make ATP using light.

Accepted Answer

Bacteriorhodopsin is a protein that abso

Question 3

Describe how thioredoxin participates in the regulation of several chloroplast enzymes by light.

Accepted Answer

Thioredoxin participates in the regulati

Question 4

How is the enzyme ADP-glucose pyrophosphorylase regulated in plants?

Accepted Answer

A)  It is activated by both inorganic phosphate and 3-phosphoglycerate. 
B)  It is activated by inorganic phosphate and unaffected by 3-phosphoglycerate. 
C)  It is activated by inorganic phosphate and inhibited by 3-phosphoglycerate. 
D)  It is inhibited by both inorganic phosphate and 3-phosphoglycerate. 
E)  It is inhibited by inorganic phosphate and activated by 3-phosphoglycerate. 
A)  It is activated by both inorganic phosphate and 3-phosphoglycerate. 
B)  It is activated by inorganic phosphate and unaffected by 3-phosphoglycerate. 
C)  It is activated by inorganic phosphate and inhibited by 3-phosphoglycerate. 
D)  It is inhibited by both inorganic phosphate and 3-phosphoglycerate. 
E)  It is inhibited by inorganic phosphate and activated by 3-phosphoglycerate.

Question 5

Which statement is NOT true about cyclic electron flow?

Accepted Answer

A)  Cyclic electron flow produces more NADPH per photon than noncyclic electron flow. 
B)  Cyclic electron flow involves only PSI. 
C)  Plastocyanin is required for cyclic electron flow. 
D)  Cyclic electron flow leads to the build-up of a proton gradient. 
E)  Cyclic electron flow does not produce O2. 
A)  Cyclic electron flow produces more NADPH per photon than noncyclic electron flow. 
B)  Cyclic electron flow involves only PSI. 
C)  Plastocyanin is required for cyclic electron flow. 
D)  Cyclic electron flow leads to the build-up of a proton gradient. 
E)  Cyclic electron flow does not produce O2.

Question 6

A precursor in the synthesis of the peptidoglycan of bacterial cell walls is UDP-:

Accepted Answer

A)  galactose. 
B)  glucose. 
C)  glucuronic acid. 
D)  N-acetylglucosamine. 
E)  penicillin. 
A)  galactose. 
B)  glucose. 
C)  glucuronic acid. 
D)  N-acetylglucosamine. 
E)  penicillin.

Question 7

Which statement is TRUE regarding ATP synthase in chloroplasts?

Accepted Answer

A)  The CF1 portion of the complex is located on the lumen side of thylakoid membranes. 
B)  This complex is homologous to the complex located in mitochondria. 
C)  This complex will act as an ATPase in membrane-free preparations. 
D)  The CF1 portion of the complex is located on the lumen side of thylakoid membranes, and this complex is homologous to the complex located in mitochondria. 
E)  This complex is both homologous to the complex located in mitochondria and will act as an ATPase in membrane-free preparations. 
A)  The CF1 portion of the complex is located on the lumen side of thylakoid membranes. 
B)  This complex is homologous to the complex located in mitochondria. 
C)  This complex will act as an ATPase in membrane-free preparations. 
D)  The CF1 portion of the complex is located on the lumen side of thylakoid membranes, and this complex is homologous to the complex located in mitochondria. 
E)  This complex is both homologous to the complex located in mitochondria and will act as an ATPase in membrane-free preparations.

Question 8

Which process occurs in photosynthesis?

Accepted Answer

A)  Carbon atoms in CO2 become reduced. 
B)  Oxygen atoms in water become oxidized. 
C)  NADP is reduced to NADPH by electron transport processes. 
D)  All of the answers are correct. 
E)  None of the answers is correct. 
A)  Carbon atoms in CO2 become reduced. 
B)  Oxygen atoms in water become oxidized. 
C)  NADP is reduced to NADPH by electron transport processes. 
D)  All of the answers are correct. 
E)  None of the answers is correct.

Question 9

Which statement is FALSE concerning xylulose-5-phosphate and ribose-5-phosphate?

Accepted Answer

A)  These molecules are isomers of each other. 
B)  These molecules are both ketopentoses. 
C)  These molecules can both be generated from ribulose 5-phosphate in a single reaction. 
D)  In the Calvin cycle, both of these are D enantiomers. 
E)  None of these statements is false. 
A)  These molecules are isomers of each other. 
B)  These molecules are both ketopentoses. 
C)  These molecules can both be generated from ribulose 5-phosphate in a single reaction. 
D)  In the Calvin cycle, both of these are D enantiomers. 
E)  None of these statements is false.

Question 10

Which statement describes shared characteristics of both oxidative phosphorylation and photophosphorylation?

Accepted Answer

A)  During electron transport, protons are exported across the outer membrane. 
B)  ATP synthesis occurs in conjunction with proton translocation. 
C)  Electron transport proceeds from compounds with lower reduction potentials than those with higher reduction potentials. 
D)  ATP synthesis occurs in conjunction with proton translocation, and electron transport proceeds from compounds with lower reduction potentials than those with higher reduction potentials. 
E)  None of these statements describes shared characteristics of both oxidative phosphorylation and photophosphorylation. 
A)  During electron transport, protons are exported across the outer membrane. 
B)  ATP synthesis occurs in conjunction with proton translocation. 
C)  Electron transport proceeds from compounds with lower reduction potentials than those with higher reduction potentials. 
D)  ATP synthesis occurs in conjunction with proton translocation, and electron transport proceeds from compounds with lower reduction potentials than those with higher reduction potentials. 
E)  None of these statements describes shared characteristics of both oxidative phosphorylation and photophosphorylation.

Question 11

Which enzyme is inhibited by fructose-2,6-bisphosphate in plants?

Accepted Answer

A)  fructose-1,6-bisphosphatase 
B)  sucrose-6-phosphate synthase 
C)  sucrose-6-phosphate phosphatase 
D)  PPi-dependent phosphofructokinase 
E)  None of these enzymes is inhibited by fructose-2,6-bisphosphate. 
A)  fructose-1,6-bisphosphatase 
B)  sucrose-6-phosphate synthase 
C)  sucrose-6-phosphate phosphatase 
D)  PPi-dependent phosphofructokinase 
E)  None of these enzymes is inhibited by fructose-2,6-bisphosphate.

Question 12

Describe the oxygenase activity of ribulose 1,5-bisphosphate carboxylase/oxygenase (rubisco) and explain why this reaction is undesirable from the point of view of a plant.

Accepted Answer

Ribulose 1,5-bisphosphate carboxylase/ox

Question 13

In what order do the following five steps occur in the photochemical reaction centers? 1) excitation of the chlorophyll a molecule at the reaction center
2) replacement of the electron in the reaction center chlorophyll
3) light excitation of antenna chlorophyll molecule
4) passage of excited electron to electron-transfer chain
5) exiton transfer to neighboring chlorophyll

Accepted Answer

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

Question 14

The experimental determination of the effectiveness of light of different colors in promoting photosynthesis is called the _____ spectrum.

Accepted Answer

A)  absorption 
B)  action 
C)  difference 
D)  reflectance 
E)  refraction 
A)  absorption 
B)  action 
C)  difference 
D)  reflectance 
E)  refraction

Question 15

In "C4" plants of tropical origin, the first intermediate into which 14CO2 is fixed is:

Accepted Answer

A)  aspartate. 
B)  phosphoenolpyruvate. 
C)  oxaloacetate. 
D)  malate. 
E)  3-phosphoglycerate. 
A)  aspartate. 
B)  phosphoenolpyruvate. 
C)  oxaloacetate. 
D)  malate. 
E)  3-phosphoglycerate.

Question 16

During carbon fixation in C4 plants, which reaction type or process does NOT occur between the conversion of phosphoenolpyruvate to pyruvate?

Accepted Answer

A)  movement of metabolites through plasmodesmata 
B)  oxidation of metabolites 
C)  ATP consumption 
D)  carboxylation 
E)  decarboxylation 
A)  movement of metabolites through plasmodesmata 
B)  oxidation of metabolites 
C)  ATP consumption 
D)  carboxylation 
E)  decarboxylation

Question 17

The major regulator of sucrose biosynthesis in plants is:

Accepted Answer

A)  fructose 2,6-bisphosphate. 
B)  fructose 1,6-bisphosphate. 
C)  sucrose. 
D)  glucose and fructose. 
E)  glucose 6-phosphate. 
A)  fructose 2,6-bisphosphate. 
B)  fructose 1,6-bisphosphate. 
C)  sucrose. 
D)  glucose and fructose. 
E)  glucose 6-phosphate.

Question 18

Which process is NOT a mechanism of regulation for sucrose-6-phosphate synthase?

Accepted Answer

A)  allosteric inhibition by phosphate 
B)  inhibition by phosphorylation 
C)  allosteric activation by fructose-6-phosphate 
D)  allosteric regulation by glucose-6-phosphate 
E)  inhibition of sucrose phosphate synthase kinase by glucose-6-phosphate 
A)  allosteric inhibition by phosphate 
B)  inhibition by phosphorylation 
C)  allosteric activation by fructose-6-phosphate 
D)  allosteric regulation by glucose-6-phosphate 
E)  inhibition of sucrose phosphate synthase kinase by glucose-6-phosphate

Question 19

Name one similarity and one difference between the biosynthesis of glycogen and the biosynthesis of cellulose.

Accepted Answer

Similarity:
Both glycogen and cellulose

Question 20

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.

Exam 20: Carbohydrate Biosynthesis in Plants and Bacteria

When transketolase acts on fructose 6-phosphate and glyceraldehyde 3-phosphate, the products are:

Some photosynthetic bacteria contain the protein bacteriorhodopsin, which absorbs light and pumps protons out of the cell directly. Briefly describe how such a cell could use bacteriorhodopsin and an H+ATPase to make ATP using light.

Describe how thioredoxin participates in the regulation of several chloroplast enzymes by light.

How is the enzyme ADP-glucose pyrophosphorylase regulated in plants?

Which statement is NOT true about cyclic electron flow?

A precursor in the synthesis of the peptidoglycan of bacterial cell walls is UDP-:

Which statement is TRUE regarding ATP synthase in chloroplasts?

Which process occurs in photosynthesis?

Which statement is FALSE concerning xylulose-5-phosphate and ribose-5-phosphate?

Which statement describes shared characteristics of both oxidative phosphorylation and photophosphorylation?

Which enzyme is inhibited by fructose-2,6-bisphosphate in plants?

Describe the oxygenase activity of ribulose 1,5-bisphosphate carboxylase/oxygenase (rubisco) and explain why this reaction is undesirable from the point of view of a plant.

The experimental determination of the effectiveness of light of different colors in promoting photosynthesis is called the _____ spectrum.

In "C4" plants of tropical origin, the first intermediate into which 14CO2 is fixed is:

During carbon fixation in C4 plants, which reaction type or process does NOT occur between the conversion of phosphoenolpyruvate to pyruvate?

The major regulator of sucrose biosynthesis in plants is:

Which process is NOT a mechanism of regulation for sucrose-6-phosphate synthase?

Name one similarity and one difference between the biosynthesis of glycogen and the biosynthesis of cellulose.

Cyclic electron flow in chloroplasts produces:

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

Some photosynthetic bacteria contain the protein bacteriorhodopsin, which absorbs light and pumps protons out of the cell directly. Briefly describe how such a cell could use bacteriorhodopsin and an H⁺ATPase to make ATP using light.

In "C₄" plants of tropical origin, the first intermediate into which ¹⁴CO₂ is fixed is:

During carbon fixation in C₄ plants, which reaction type or process does NOT occur between the conversion of phosphoenolpyruvate to pyruvate?