Question 1

What is a common mechanistic feature of kinases?

Accepted Answer

A)  Phosphoryl groups are transferred from a substrate with high phosphoryl-transfer potential to AMP. 
B)  Binding of substrate causes a large conformation change that results in cleft closing. 
C)  All phosphorylation reactions are specific for monosaccharides. 
D)  Phosphorylation always uses ATP as a substrate. 
E)  None of the answers is correct. 
A)  Phosphoryl groups are transferred from a substrate with high phosphoryl-transfer potential to AMP. 
B)  Binding of substrate causes a large conformation change that results in cleft closing. 
C)  All phosphorylation reactions are specific for monosaccharides. 
D)  Phosphorylation always uses ATP as a substrate. 
E)  None of the answers is correct.

Question 2

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 3

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 4

Glycolysis produces a net of ________ moles of ATP per 1 mole of glucose.

Accepted Answer

The answer of Glycolysis produces a net of ________ moles...

Question 5

Both hexokinase and glucokinase phosphorylate glucose.The function of glucokinase is to phosphorylate glucose in liver cells as a means to regulate blood-sugar levels.Would you expect its KM to be higher or lower than hexokinase? Explain your answer.

Accepted Answer

Glucokinase must be responsive to elevat

Question 6

What is the additional metabolite that is required for the conversion of 3-phosphoglycerate to 2-phosphoglycerate?

Accepted Answer

A)  1-phosphoglycerate 
B)  diacylglycerol 
C)  NADH 
D)  2,3-bisphosphoglycerate 
E)  1,3-bisphosphoglycerate 
A)  1-phosphoglycerate 
B)  diacylglycerol 
C)  NADH 
D)  2,3-bisphosphoglycerate 
E)  1,3-bisphosphoglycerate

Question 7

The ________________ cycle refers to the metabolic reactions by which glucose is converted into lactate in skeletal muscle,and then lactate is converted back into glucose in the liver.

Accepted Answer

The answer of The ________________ cycle refers to the metabolic...

Question 8

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 9

The formation of ATP is due to direct transfer of a phosphoryl group and is called ___________________.

Accepted Answer

substrate-

Question 10

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 11

How is glycolysis maintained under anaerobic conditions?

Accepted Answer

Pyruvate can be reduced to eit

Question 12

Why is it more sensible for phosphofructokinase to be an important control step,rather than hexokinase?

Accepted Answer

Phosphofructokinase catalyzes the first

Question 13

Which metabolic steps differ between glycolysis and gluconeogenesis?

Accepted Answer

There are three irreversible steps in gl

Question 14

The Embden Meyerhof pathway is also known as _____.

Accepted Answer

A)  pentose phosphate pathway 
B)  glycolysis 
C)  citric acid cycle 
D)  gluconeogenesis 
E)  None of the answers is correct. 
A)  pentose phosphate pathway 
B)  glycolysis 
C)  citric acid cycle 
D)  gluconeogenesis 
E)  None of the answers is correct.

Question 15

What is substrate level phosphorylation?

Accepted Answer

A)  phosphorylation of AMP by ATP 
B)  ATP synthesis when the phosphate donor is a substrate with high phosphoryl transfer potential 
C)  phosphorylation of glycolytic intermediates 
D)  phosphorylation of ATP coupled to an ion gradient 
E)  ATP and AMP synthesis from two molecules of ADP 
A)  phosphorylation of AMP by ATP 
B)  ATP synthesis when the phosphate donor is a substrate with high phosphoryl transfer potential 
C)  phosphorylation of glycolytic intermediates 
D)  phosphorylation of ATP coupled to an ion gradient 
E)  ATP and AMP synthesis from two molecules of ADP

Question 16

What type of organism cannot survive in the presence of oxygen?

Accepted Answer

A)  obligate anaerobes 
B)  facultative anaerobes 
C)  obligate aerobes 
D)  facultative aerobes 
E)  None of the answers is correct. 
A)  obligate anaerobes 
B)  facultative anaerobes 
C)  obligate aerobes 
D)  facultative aerobes 
E)  None of the answers is correct.

Question 17

Which of the following is an allosteric inhibitor of phosphofructokinase?

Accepted Answer

A)  NADH 
B)  ATP 
C)  AMP 
D)  fructose 1,6-bisphosphate 
E)  None of the answers is correct. 
A)  NADH 
B)  ATP 
C)  AMP 
D)  fructose 1,6-bisphosphate 
E)  None of the answers is correct.

Question 18

What is the function of a thioester intermediate such as the one formed from GAP?

Accepted Answer

A)  It speeds up the actual reaction so that more product can be made. 
B)  The thioester shifts the equilibrium of the first stage of the reaction. 
C)  The thioester allows the two-step reaction to be coupled so the second reaction, the energetically unfavorable phosphorylation, can proceed. 
D)  The thioester intermediate induces a conformational change that alters the enzyme specificity. 
E)  The thioester prevents the formation of metabolically unfavorable side products. 
A)  It speeds up the actual reaction so that more product can be made. 
B)  The thioester shifts the equilibrium of the first stage of the reaction. 
C)  The thioester allows the two-step reaction to be coupled so the second reaction, the energetically unfavorable phosphorylation, can proceed. 
D)  The thioester intermediate induces a conformational change that alters the enzyme specificity. 
E)  The thioester prevents the formation of metabolically unfavorable side products.

Question 19

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 20

The first step in gluconeogenesis is the ___________________ of pyruvate to form oxaloacetate.

Accepted Answer

The answer of The first step in gluconeogenesis is the...

Exam 16: Glycolysis and Gluconeogenesis

What is a common mechanistic feature of kinases?

Lactose intolerance is caused by a deficiency of

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

Glycolysis produces a net of ________ moles of ATP per 1 mole of glucose.

Both hexokinase and glucokinase phosphorylate glucose.The function of glucokinase is to phosphorylate glucose in liver cells as a means to regulate blood-sugar levels.Would you expect its KM to be higher or lower than hexokinase? Explain your answer.

What is the additional metabolite that is required for the conversion of 3-phosphoglycerate to 2-phosphoglycerate?

The ________________ cycle refers to the metabolic reactions by which glucose is converted into lactate in skeletal muscle,and then lactate is converted back into glucose in the liver.

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

The formation of ATP is due to direct transfer of a phosphoryl group and is called ___________________.

How are the glycolytic enzymes regulated?

How is glycolysis maintained under anaerobic conditions?

Why is it more sensible for phosphofructokinase to be an important control step,rather than hexokinase?

Which metabolic steps differ between glycolysis and gluconeogenesis?

The Embden Meyerhof pathway is also known as _____.

What is substrate level phosphorylation?

What type of organism cannot survive in the presence of oxygen?

Which of the following is an allosteric inhibitor of phosphofructokinase?

What is the function of a thioester intermediate such as the one formed from GAP?

What is the function of glyceraldehyde 3-phosphate dehydrogenase?

The first step in gluconeogenesis is the ___________________ of pyruvate to form oxaloacetate.

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

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

Oxidative Phosphorylation

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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Both hexokinase and glucokinase phosphorylate glucose.The function of glucokinase is to phosphorylate glucose in liver cells as a means to regulate blood-sugar levels.Would you expect its K_M to be higher or lower than hexokinase? Explain your answer.