Question 1

Explain why disaccharides are more common in nature than monosaccharides.

Accepted Answer

Disaccharides are sugars formed by a con

Question 2

Three reactions in glycolysis operate far from equilibrium and are potential sites for major flux control. List the three enzymes and explain why each enzyme is or is not the major control site of glycolysis.

Accepted Answer

Hexokinase, phosphofructokinase-1, and p

Question 3

Distinguish between D and L isomers.

Accepted Answer

A)  D is right handed and L is left handed. 
B)  D is left handed and L is right handed. 
C)  D and L only differ in the position of one chiral center. 
D)  D is the boat conformation and L is the chair conformation. 
A)  D is right handed and L is left handed. 
B)  D is left handed and L is right handed. 
C)  D and L only differ in the position of one chiral center. 
D)  D is the boat conformation and L is the chair conformation.

Question 4

In the following figure, what is the linkage between the two monosaccharide units and is this a reducing sugar?

Accepted Answer

A)  "$\alpha$1$\rightarrow$$\beta$2, nonreducing" 
B)  "$\alpha$1$\rightarrow$$\alpha$1, nonreducing" 
C)  "$\alpha$1$\rightarrow$$\beta$2, reducing" 
D)  "$\alpha$1$\rightarrow$$\alpha$2, reducing" 
A)  "$\alpha$1$\rightarrow$$\beta$2, nonreducing" 
B)  "$\alpha$1$\rightarrow$$\alpha$1, nonreducing" 
C)  "$\alpha$1$\rightarrow$$\beta$2, reducing" 
D)  "$\alpha$1$\rightarrow$$\alpha$2, reducing"

Question 5

Review the figure below. Shared intermediates are used so effectively in coupled reactions because they

Accepted Answer

A)  allow products to diffuse through membrane to increase concentration gradient. 
B)  increase the value of $\Delta$G $\degree$' . 
C)  decrease the value of Q. 
D)  limit product diffusion and allow intermediates to channel from one enzyme to the next. 
A)  allow products to diffuse through membrane to increase concentration gradient. 
B)  increase the value of $\Delta$G $\degree$' . 
C)  decrease the value of Q. 
D)  limit product diffusion and allow intermediates to channel from one enzyme to the next.

Question 6

Given figures A and B below, label the chiral center on each and state if the molecule is a D or L enantiomer.

Accepted Answer

Molecule A is the D

Question 7

Explain the difference between a Fisher projection and a Haworth projection.

Accepted Answer

A)  Fischer projections illustrate the cyclic form, whereas Haworth projections represent the linear form. 
B)  The Haworth projection illustrates the six-membered rings, whereas the Fischer projection represents the five-membered rings. 
C)  Haworth projections illustrate the cyclic form, whereas Fischer projections represent the linear form. 
D)  Fischer projections show the boat conformation, whereas Haworth projections show the chair conformation. 
A)  Fischer projections illustrate the cyclic form, whereas Haworth projections represent the linear form. 
B)  The Haworth projection illustrates the six-membered rings, whereas the Fischer projection represents the five-membered rings. 
C)  Haworth projections illustrate the cyclic form, whereas Fischer projections represent the linear form. 
D)  Fischer projections show the boat conformation, whereas Haworth projections show the chair conformation.

Question 8

What is the main difference between energy conversion pathways and metabolite synthesis pathways?

Accepted Answer

A)  Energy conversion pathways produce ATP. 
B)  Energy conversion pathways deplete ATP. 
C)  Metabolite synthesis pathway uses ATP to break down metabolites. 
D)  Metabolite synthesis pathway uses ATP to break down pyruvate. 
A)  Energy conversion pathways produce ATP. 
B)  Energy conversion pathways deplete ATP. 
C)  Metabolite synthesis pathway uses ATP to break down metabolites. 
D)  Metabolite synthesis pathway uses ATP to break down pyruvate.

Question 9

A shared intermediate can be defined as a molecule that is

Accepted Answer

A)  a reactant in a pathway. 
B)  the final product of a pathway. 
C)  the final product of a pathway and the reactant of the next pathway. 
D)  favorable to produce. 
A)  a reactant in a pathway. 
B)  the final product of a pathway. 
C)  the final product of a pathway and the reactant of the next pathway. 
D)  favorable to produce.

Question 10

Define ketose.

Accepted Answer

A)  Only ketose molecules have CH2OH. 
B)  Ketose molecules have ketone functional groups. 
C)  Ketose molecules have aldehyde functional groups. 
D)  Ketose molecules are all five-membered rings. 
A)  Only ketose molecules have CH2OH. 
B)  Ketose molecules have ketone functional groups. 
C)  Ketose molecules have aldehyde functional groups. 
D)  Ketose molecules are all five-membered rings.

Question 11

In the following series of reactions, what is the shared intermediate?

Accepted Answer

A)  glucose-6-P 
B)  fructose-6-P 
C)  ATP 
D)  fructose-1,6-P 
A)  glucose-6-P 
B)  fructose-6-P 
C)  ATP 
D)  fructose-1,6-P

Question 12

Using the table below, explain why glycolysis is an overall favorable reaction pathway.

Accepted Answer

A) Overall the pathway is $\Delta$G > 0. B) Overall the pathway is $\Delta$G = 0. C) Overall the pathway is $\Delta$G < 0. D) Overall the pathway is $\Delta$G < 1. A) Overall the pathway is $\Delta$G > 0. B) Overall the pathway is $\Delta$G = 0. C) Overall the pathway is $\Delta$G < 0. D) Overall the pathway is $\Delta$G < 1.

Question 13

What is the relationship between the molecules in the figure below?

Accepted Answer

A)  They are isomers. 
B)  They are anomers. 
C)  They are epimers. 
D)  They are identical. 
A)  They are isomers. 
B)  They are anomers. 
C)  They are epimers. 
D)  They are identical.

Question 14

During the cyclization of D-glucose, where is a new chiral center formed?

Accepted Answer

A)  C-1 
B)  C-3 
C)  C-4 
D)  C-5 
A)  C-1 
B)  C-3 
C)  C-4 
D)  C-5

Question 15

The test using copper to determine blood glucose levels is called a test.

Accepted Answer

A)  glycolysis 
B)  phosphorylation 
C)  Benedict's 
D)  McKee's 
A)  glycolysis 
B)  phosphorylation 
C)  Benedict's 
D)  McKee's

Question 16

Differentiate among epimers, anomers, and isomers.

Accepted Answer

Epimers are two monosaccharides of same

Question 17

List three ways in which flux is controlled through glycolysis.

Accepted Answer

A)  regulation of aldolase, PFK-1, and supply and demand of intermediates 
B)  regulation of glucokinase, fructokinase, and number of intermediates 
C)  regulation of glucokinase, PFK-1, and concentration of glucose 
D)  regulation of glucokinase, PFK-1, and supply and demand of intermediates 
A)  regulation of aldolase, PFK-1, and supply and demand of intermediates 
B)  regulation of glucokinase, fructokinase, and number of intermediates 
C)  regulation of glucokinase, PFK-1, and concentration of glucose 
D)  regulation of glucokinase, PFK-1, and supply and demand of intermediates

Question 18

Using the figure below, discuss how ATP, ADP, AMP, and fructose-2,6-BP are an allosteric regulator of phosphofructokinase-1.

Accepted Answer

The activity of PFK-1 is inhibited by hi

Question 19

In the presence of lactase, lactose is cleaved into the monosaccharides glucose and

Accepted Answer

A)  glucose. 
B)  fructose. 
C)  galactose. 
D)  maltose. 
A)  glucose. 
B)  fructose. 
C)  galactose. 
D)  maltose.

Question 20

In the presence of high concentrations of ADP and F6P, how does the equilibrium shift between the T state and R state of PFK-1? High concentrations of ADP and F6P

Accepted Answer

A)  shift equilibrium to the R state. 
B)  shift equilibrium to the T state. 
C)  do not bind to PFK. 
D)  dancel each other out and have no effect. 
A)  shift equilibrium to the R state. 
B)  shift equilibrium to the T state. 
C)  do not bind to PFK. 
D)  dancel each other out and have no effect.

Exam 9: Glycolysis: a Paradigm of Metabolic Regulation

Explain why disaccharides are more common in nature than monosaccharides.

Three reactions in glycolysis operate far from equilibrium and are potential sites for major flux control. List the three enzymes and explain why each enzyme is or is not the major control site of glycolysis.

Distinguish between D and L isomers.

In the following figure, what is the linkage between the two monosaccharide units and is this a reducing sugar?

Review the figure below. Shared intermediates are used so effectively in coupled reactions because they

Given figures A and B below, label the chiral center on each and state if the molecule is a D or L enantiomer.

Explain the difference between a Fisher projection and a Haworth projection.

What is the main difference between energy conversion pathways and metabolite synthesis pathways?

A shared intermediate can be defined as a molecule that is

Define ketose.

In the following series of reactions, what is the shared intermediate?

Using the table below, explain why glycolysis is an overall favorable reaction pathway.

What is the relationship between the molecules in the figure below?

During the cyclization of D-glucose, where is a new chiral center formed?

The test using copper to determine blood glucose levels is called a test.

Differentiate among epimers, anomers, and isomers.

List three ways in which flux is controlled through glycolysis.

Using the figure below, discuss how ATP, ADP, AMP, and fructose-2,6-BP are an allosteric regulator of phosphofructokinase-1.

In the presence of lactase, lactose is cleaved into the monosaccharides glucose and

In the presence of high concentrations of ADP and F6P, how does the equilibrium shift between the T state and R state of PFK-1? High concentrations of ADP and F6P

Principles of Biochemistry

Physical Biochemistry: Energy Conversion, Water, and Membranes

Nucleic Acid Structure and Function

Protein Structure

Methods in Protein Biochemistry

Protein Function

Enzyme Mechanisms

Cell Signaling Systems

The Citrate Cycle

Oxidative Phosphorylation

Photosynthesis

Carbohydrate Structure and Function

Carbohydrate Metabolism

Lipid Structure and Function

Lipid Metabolism

Amino Acid Metabolism

Nucleotide Metabolism

Metabolic Integration

DNA Replication, Repair, and Recombination

RNA Synthesis, Processing, and Gene Silencing

Protein Synthesis, Posttranslational Modification, and Transport

Gene Regulation

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