Question 1

What astounding discovery was made by the Buchners?

Accepted Answer

When the Buchners demonstrated

Question 2

What two isomerization reactions occur in glycolysis? Why are these steps necessary?

Accepted Answer

Glucose-6-phosphate is isomerized to fru

Question 3

During exercise, how is glycolysis regulated by feedforward stimulation?

Accepted Answer

Exercise increases the abundance of fruc

Question 4

Two primary raw materials for gluconeogenesis in the human liver are

Accepted Answer

A)  galactose and sucrose. 
B)  acetate and oxaloacetate. 
C)  lactate and alanine. 
D)  fructose and alanine. 
E)  lactose and lactate. 
A)  galactose and sucrose. 
B)  acetate and oxaloacetate. 
C)  lactate and alanine. 
D)  fructose and alanine. 
E)  lactose and lactate.

Question 5

Which metabolic steps differ between glycolysis and gluconeogenesis?

Accepted Answer

There are three irreversible steps in gl

Question 6

How are gluconeogenesis and glycolysis regulated reciprocally?

Accepted Answer

The enzymes involved in two substrate cy

Question 7

Fructose can enter glycolysis at two distinct points, depending on the tissue. How is fructose metabolized in adipose tissue?

Accepted Answer

A)  Fructose is cleaved to two molecules of GAP. 
B)  Fructose is converted to fructose-1-phosphate. 
C)  Fructose is converted to fructose-6-phosphate. 
D)  Fructose is cleaved to GAP and DHAP. 
E)  Fructose is converted to glucose, which enters the pathway. 
A)  Fructose is cleaved to two molecules of GAP. 
B)  Fructose is converted to fructose-1-phosphate. 
C)  Fructose is converted to fructose-6-phosphate. 
D)  Fructose is cleaved to GAP and DHAP. 
E)  Fructose is converted to glucose, which enters the pathway.

Question 8

Lactose intolerance is caused by a deficiency of

Accepted Answer

A)  lactase. 
B)  elastase. 
C)  lactose. 
D)  sucrase. 
E)  None of the answers is correct. 
A)  lactase. 
B)  elastase. 
C)  lactose. 
D)  sucrase. 
E)  None of the answers is correct.

Question 9

What two 3-carbon molecules are generated by the cleavage of fructose-1,6-bisphosphate?

Accepted Answer

A)  glyceraldehyde-3-phosphate and 3-phosphoglycerate 
B)  glyceraldehyde-3-phosphate and dihydroxyacetone phosphate 
C)  pyruvate and phosphoenolpyruvate 
D)  enolase and 2-phosphoglycerate 
E)  glyceraldehyde-3-phosphate and pyruvate 
A)  glyceraldehyde-3-phosphate and 3-phosphoglycerate 
B)  glyceraldehyde-3-phosphate and dihydroxyacetone phosphate 
C)  pyruvate and phosphoenolpyruvate 
D)  enolase and 2-phosphoglycerate 
E)  glyceraldehyde-3-phosphate and pyruvate

Question 10

How many high-energy phosphate bonds are expended in gluconeogenesis?

Accepted Answer

A)  three 
B)  six 
C)  two 
D)  four 
E)  one 
A)  three 
B)  six 
C)  two 
D)  four 
E)  one

Question 11

How are the glycolytic enzymes regulated?

Accepted Answer

A)  transcriptional control 
B)  reversible phosphorylation 
C)  allosteric control 
D)  All of the answers are correct. 
E)  reversible phosphorylation and allosteric control 
A)  transcriptional control 
B)  reversible phosphorylation 
C)  allosteric control 
D)  All of the answers are correct. 
E)  reversible phosphorylation and allosteric control

Question 12

What is the purpose of phosphorylating glucose in the cytosol?

Accepted Answer

A)  to trap glucose in the cell 
B)  to destabilize glucose and facilitate the next series of metabolic steps 
C)  to convert it to a more soluble form 
D)  to slow the transport of glucose into the cell 
E)  Both A and B are correct. 
A)  to trap glucose in the cell 
B)  to destabilize glucose and facilitate the next series of metabolic steps 
C)  to convert it to a more soluble form 
D)  to slow the transport of glucose into the cell 
E)  Both A and B are correct.

Question 13

What is the function of glyceraldehyde 3-phosphate dehydrogenase?

Accepted Answer

A)  oxidation of an aldehyde by NAD+ and formation of acyl-phosphate 
B)  oxidation of an alcohol to an aldehyde by NAD+ 
C)  dehydration and dephosphorylation of GAP 
D)  hydrolysis of GAP 
E)  removal of the 3-phosphoryl-group from GAP 
A)  oxidation of an aldehyde by NAD+ and formation of acyl-phosphate 
B)  oxidation of an alcohol to an aldehyde by NAD+ 
C)  dehydration and dephosphorylation of GAP 
D)  hydrolysis of GAP 
E)  removal of the 3-phosphoryl-group from GAP

Question 14

What transporter is responsible for fructose uptake in the intestine?

Accepted Answer

A)  GLUT1 
B)  GLUT2 
C)  GLUT3 
D)  GLUT4 
E)  GLUT5 
A)  GLUT1 
B)  GLUT2 
C)  GLUT3 
D)  GLUT4 
E)  GLUT5

Question 15

At equilibrium, there is far more DHAP than GAP. Yet the conversion of DHAP by triose phosphate isomerase proceeds readily. Why?

Accepted Answer

The GAP formed is immediately

Question 16

How is the conversion of phosphoenolpyruvate to pyruvate accompanied by ATP formation?

Accepted Answer

The enol phosphate possesses v

Question 17

What two functions are attributed to substrate cycles?

Accepted Answer

The substrate cycles regulate

Question 18

The catalytic mechanism of the isomerization of a ketose into an aldose proceeds through an _________________ intermediate.

Accepted Answer

The answer of The catalytic mechanism of the isomerization of...

Question 19

Describe the biochemical explanation for galactosemia.

Accepted Answer

Galactose is metabolized by conversion t

Question 20

In alcoholic fermentation, the decarboxylation of pyruvate requires a coenzyme that contains the vitamin ______________.

Accepted Answer

The answer of In alcoholic fermentation, the decarboxylation of pyruvate...

Exam 16: Glycolysis and Gluconeogenesis

What astounding discovery was made by the Buchners?

What two isomerization reactions occur in glycolysis? Why are these steps necessary?

During exercise, how is glycolysis regulated by feedforward stimulation?

Two primary raw materials for gluconeogenesis in the human liver are

Which metabolic steps differ between glycolysis and gluconeogenesis?

How are gluconeogenesis and glycolysis regulated reciprocally?

Fructose can enter glycolysis at two distinct points, depending on the tissue. How is fructose metabolized in adipose tissue?

Lactose intolerance is caused by a deficiency of

What two 3-carbon molecules are generated by the cleavage of fructose-1,6-bisphosphate?

How many high-energy phosphate bonds are expended in gluconeogenesis?

How are the glycolytic enzymes regulated?

What is the purpose of phosphorylating glucose in the cytosol?

What is the function of glyceraldehyde 3-phosphate dehydrogenase?

What transporter is responsible for fructose uptake in the intestine?

At equilibrium, there is far more DHAP than GAP. Yet the conversion of DHAP by triose phosphate isomerase proceeds readily. Why?

How is the conversion of phosphoenolpyruvate to pyruvate accompanied by ATP formation?

What two functions are attributed to substrate cycles?

The catalytic mechanism of the isomerization of a ketose into an aldose proceeds through an _________________ intermediate.

Describe the biochemical explanation for galactosemia.

In alcoholic fermentation, the decarboxylation of pyruvate requires a coenzyme that contains the vitamin ______________.

Biochemistry: an Evolving Science

Protein Composition and Structure

Exploring Proteins and Proteomes

DNA, RNA, and the Flow of Genetic Information

Exploring Genes and Genomes

Exploring Evolution and Bioinformatics

Hemoglobin: a Portrait of a Protein in Action

Enzymes: Basic Concepts and Kinetics

Oxidative Phosphorylation

Catalytic Strategies

Regulatory Strategies

Carbohydrates

Lipids and Cell Membranes

Membrane Channels and Pumps

Signal-Transduction Pathways

Metabolism: Basic Concepts and Design

The Citric Acid Cycle

The Light Reactions of Photosynthesis

The Calvin Cycle and the Pentose Phosphate Pathway

Glycogen Metabolism

Fatty Acid Metabolism

Protein Turnover and Amino Acid Catabolism

The Biosynthesis of Amino Acids

Nucleotide Biosynthesis

Biosynthesis of Membrane Lipids and Steroids

The Integration of Metabolism

DNA Replication, Repair, and Recombination

Rna Synthesis and Processing

Protein Synthesis

The Control of Gene Expression in Prokaryotes

The Control of Gene Expression in Eukaryotes

Sensory Systems

The Immune System

Molecular Motors

Drug Development

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