Question 1

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 2

Sucrose is a nonreducing sugar.Why?

Accepted Answer

A)  Sucrose does not contain an aldehyde functional group. 
B)  Sucrose does not react with heat. 
C)  Sucrose is a pyranose that cannot be reacted with copper. 
D)  Sucrose is a disaccharide that cannot be converted to an open chain. 
A)  Sucrose does not contain an aldehyde functional group. 
B)  Sucrose does not react with heat. 
C)  Sucrose is a pyranose that cannot be reacted with copper. 
D)  Sucrose is a disaccharide that cannot be converted to an open chain.

Question 3

The first reaction in glycolysis that produces a high-energy compound is catalyzed by

Accepted Answer

A)  aldolase. 
B)  triose phosphate isomerase. 
C)  enolase. 
D)  phosphofructokinase-1. 
A)  aldolase. 
B)  triose phosphate isomerase. 
C)  enolase. 
D)  phosphofructokinase-1.

Question 4

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 5

Name the following disaccharide using descriptive nomenclature.

Accepted Answer

A)  Glc(   1    2)Fru 
B)  Glc(   1    2)Glc 
C)  Gal(   1  4)Glc 
D)  Glc(   1    4)Glc 
A)  Glc(   1    2)Fru 
B)  Glc(   1    2)Glc 
C)  Gal(   1  4)Glc 
D)  Glc(   1    4)Glc

Question 6

The NADH that is produced by glycolysis under anaerobic conditions is regenerated to NAD+ by the conversion of

Accepted Answer

A)  acetaldehyde  Ethanol. 
B)  lactate  Pyruvate. 
C)  phosphoenolpyruvate  Pyruvate. 
D)  pyruvate  Lactate. 
A)  acetaldehyde  Ethanol. 
B)  lactate  Pyruvate. 
C)  phosphoenolpyruvate  Pyruvate. 
D)  pyruvate  Lactate.

Question 7

What is the fate of pyruvate in the presence of yeast,Saccharomyces cerevisiae?

Accepted Answer

A)  converts to CO2 and ethanol 
B)  converts to H2O and CO2 
C)  converts to lactate and ethanol 
D)  converts to lactate and glucose 
A)  converts to CO2 and ethanol 
B)  converts to H2O and CO2 
C)  converts to lactate and ethanol 
D)  converts to lactate and glucose

Question 8

Distinguish between the energy investment of stage 1 and stage 2 of glycolysis.

Accepted Answer

In glycolysis the first five r

Question 9

To produce 4 ATP requires 122 kJ/mol.Which reactions in the glycolytic pathway produce enough energy to be able to overcome this deficit?

Accepted Answer

A)  enolase, phosphofructokinase-1, and pyruvate kinase 
B)  hexokinase, phosphofructokinase-1, and pyruvate kinase 
C)  phosphofructokinase-1, aldolase, and pyruvate kinase 
D)  hexokinase, enolase, and pyruvate kinase 
A)  enolase, phosphofructokinase-1, and pyruvate kinase 
B)  hexokinase, phosphofructokinase-1, and pyruvate kinase 
C)  phosphofructokinase-1, aldolase, and pyruvate kinase 
D)  hexokinase, enolase, and pyruvate kinase

Question 10

What would the effect be of a lack of lactate dehydrogenase?

Accepted Answer

A)  buildup of glucose 
B)  buildup of CO2 
C)  deficiency of ATP 
D)  deficiency of pyruvate 
A)  buildup of glucose 
B)  buildup of CO2 
C)  deficiency of ATP 
D)  deficiency of pyruvate

Question 11

For the following reaction A $\to$ B,if at equilibrium   > 0,what can be said about the directionality of the reaction?

Accepted Answer

A)  strongly favored in the forward direction 
B)  strongly favored in the reverse direction 
C)  strongly favored in both directions 
D)  Not enough information is given. 
A)  strongly favored in the forward direction 
B)  strongly favored in the reverse direction 
C)  strongly favored in both directions 
D)  Not enough information is given.

Question 12

Which of these cofactors participates directly in MOST of the redox reactions in the fermentation of glucose to lactate?

Accepted Answer

A)  ADP 
B)  ATP 
C)  NAD+/NADH 
D)  FAD/FADH2 
A)  ADP 
B)  ATP 
C)  NAD+/NADH 
D)  FAD/FADH2

Question 13

What advantage is there to phosphoglycerate kinase having an open and closed configuration?

Accepted Answer

A)  It allows water to be trapped in the active site along with the substrate. 
B)  It forces covalent binding of the substrate to the enzyme active site. 
C)  The induced-fit mechanism maximizes accessibility of active site without sacrificing hydrophobic environment. 
D)  Changing of the configuration of the enzyme makes the reaction exergonic. 
A)  It allows water to be trapped in the active site along with the substrate. 
B)  It forces covalent binding of the substrate to the enzyme active site. 
C)  The induced-fit mechanism maximizes accessibility of active site without sacrificing hydrophobic environment. 
D)  Changing of the configuration of the enzyme makes the reaction exergonic.

Question 14

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 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

Which of the following compounds contains a "high-energy" bond and is used to produce ATP by substrate-level phosphorylation in glycolysis?

Accepted Answer

A)  glucose 
B)  fructose-1,6-BP 
C)  3-phosphoglycerate 
D)  1,3-bisphosphoglycerate 
A)  glucose 
B)  fructose-1,6-BP 
C)  3-phosphoglycerate 
D)  1,3-bisphosphoglycerate

Question 17

Which of the following is the correct formula for glucose?

Accepted Answer

A)  C12H22O11 
B)  C6H12O6 
C)  C6H6O6 
D)  C14N2H18O5 
A)  C12H22O11 
B)  C6H12O6 
C)  C6H6O6 
D)  C14N2H18O5

Question 18

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 19

Which enzyme is the main regulator of glycolysis?

Accepted Answer

A)  hexokinase 
B)  PFK-1 
C)  pyruvate kinase 
D)  aldolase 
A)  hexokinase 
B)  PFK-1 
C)  pyruvate kinase 
D)  aldolase

Question 20

During glycolysis,the steps between glucose and formation of glyceraldehyde-3-phosphate

Accepted Answer

A)  consume 2 ATP and 2 NADH. 
B)  consume 2 ATP. 
C)  produce 2 ADP and 2 NADH. 
D)  produce 2 ATP and 2 NADH. 
A)  consume 2 ATP and 2 NADH. 
B)  consume 2 ATP. 
C)  produce 2 ADP and 2 NADH. 
D)  produce 2 ATP and 2 NADH.

Exam 9: Glycolysis: a Paradigm of Metabolic Regulation

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

Sucrose is a nonreducing sugar.Why?

The first reaction in glycolysis that produces a high-energy compound is catalyzed by

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

Name the following disaccharide using descriptive nomenclature.

The NADH that is produced by glycolysis under anaerobic conditions is regenerated to NAD+ by the conversion of

What is the fate of pyruvate in the presence of yeast,Saccharomyces cerevisiae?

Distinguish between the energy investment of stage 1 and stage 2 of glycolysis.

To produce 4 ATP requires 122 kJ/mol.Which reactions in the glycolytic pathway produce enough energy to be able to overcome this deficit?

What would the effect be of a lack of lactate dehydrogenase?

For the following reaction A →\to→ B,if at equilibrium > 0,what can be said about the directionality of the reaction?

Which of these cofactors participates directly in MOST of the redox reactions in the fermentation of glucose to lactate?

What advantage is there to phosphoglycerate kinase having an open and closed configuration?

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

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

Which of the following compounds contains a "high-energy" bond and is used to produce ATP by substrate-level phosphorylation in glycolysis?

Which of the following is the correct formula for glucose?

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

Which enzyme is the main regulator of glycolysis?

During glycolysis,the steps between glucose and formation of glyceraldehyde-3-phosphate

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

Filters

The NADH that is produced by glycolysis under anaerobic conditions is regenerated to NAD⁺ by the conversion of

For the following reaction A $\to$ B,if at equilibrium $For the following reaction A \to B,if at equilibrium > 0,what can be said about the directionality of the reaction?$ > 0,what can be said about the directionality of the reaction?