Question 1

Catabolism of a fatty acid produces more than twice the energy per gram as glucose (in terms of moles of ATP generated).

Accepted Answer

A) True 
 B)False

Question 2

The glycerol formed from triacylglycerol hydrolysis is converted in two steps to dihydroxyacetone phosphate.

Accepted Answer

A) True 
 B)False

Question 3

Gluconeogenesis is not a commonly used metabolic pathway when carbohydrate intake is high.

Accepted Answer

A) True 
 B)False

Question 4

Ketogenesis is the synthesis of ketone bodies from acetyl CoA.

Accepted Answer

A) True 
 B)False

Question 5

Which quantities need to be considered in determining the ATP yield from the complete catabolism of a fatty acid?

Accepted Answer

A) The ATP used up in the synthesis of the acyl CoA 
B) The ATP generated from coenzymes produced during b-oxidation 
C) The ATP that results from the catabolism of each acetyl CoA 
D) All of the quantities need to be considered.

Question 6

Glucosamine,shown below,is a competitive inhibitor of the enzyme hexokinase,which catalyzes the phosphorylation of glucose in the first step of glycolysis (Eqn. 1 below). Which statement best describes the inhibition by glucosamine?

Accepted Answer

A) Glucosamine reacts with glucose,preventing glucose from binding to the active site of hexokinase. 
B) Glucosamine binds to the active site of hexokinase,preventing glucose from binding. 
C) Glucosamine stabilizes the active site of hexokinase,preventing glucose 6-phosphate from being released. 
D) Glucosamine binds to the surface of hexokinase,causing a change in shape of the enzyme and the active site,preventing glucose from binding.

Question 7

How is pyruvate converted to acetyl CoA?

Accepted Answer

A) Under aerobic conditions 
B) Under anaerobic conditions 
C) During fermentation 
D) This conversion is favorable under all of the conditions.

Question 8

Six of the steps of gluconeogenesis use the same enzymes as used in glycolysis.

Accepted Answer

A) True 
 B)False

Question 9

When energy demands are low,glucose is stored as the polymer ________ in the liver and muscles.

Accepted Answer

The answer of When energy demands are low,glucose is stored...

Question 10

Which factors increase the rate of gluconeogenesis?

Accepted Answer

A) High glycogen reserves 
B) Low carbohydrate diet 
C) High carbohydrate diet 
D) Low oxygen concentration

Question 11

Glycolysis is a cyclic,10-step pathway.

Accepted Answer

A) True 
 B)False

Question 12

Which statement best describes the energy requirement for the conversion of a fatty acid to a thioester with coenzyme A in the β-oxidation of a fatty acid?

Accepted Answer

A) This process requires energy. 
B) This process is energy neutral-energy is neither required nor released. 
C) This process releases energy. 
D) Whether energy is required or released depends on the identity of the fatty acid being oxidized.

Question 13

Transamination is the transfer of an amino group from a(n)_____to a(n)________,usually α-ketoglutarate.

Accepted Answer

The answer of Transamination is the transfer of an amino...

Question 14

In fermentation,the six carbon atoms of glucose are converted to three molecules of ethanol.

Accepted Answer

A) True 
 B)False

Question 15

What are the products formed in the transamination reaction shown?

Accepted Answer

A)   
B)   
C)   
D)

Question 16

The breakdown of amino acids forms NH4+,which enters the urea cycle to form urea,and a carbon skeleton that is metabolized to either pyruvate,acetyl CoA,or an intermediate in the citric acid cycle.

Accepted Answer

A) True 
 B)False

Question 17

In oxidative deamination,glutamate is re-converted to α-ketoglutarate,which can undergo transamination with another molecule of an amino acid and the cycle repeats.

Accepted Answer

A) True 
 B)False

Question 18

Conceptually,gluconeogenesis is the reverse of glycolysis; that is,two molecules of pyruvate are converted to glucose by a stepwise pathway that passes through all of the same intermediates encountered in glycolysis.

Accepted Answer

A) True 
 B)False

Question 19

When acetyl CoA levels exceed the capacity of the citric acid cycle,acetyl CoA is converted to ketone bodies.

Accepted Answer

A) True 
 B)False

Question 20

The reduction of acetaldehyde,shown below,is the last step in the fermentation process. What is the product of the reduction of acetaldehyde?

Accepted Answer

A)   
B)   
C)   
D)

Exam 24: Carbohydrate,lipid,and Protein Metabolism

Catabolism of a fatty acid produces more than twice the energy per gram as glucose (in terms of moles of ATP generated).

The glycerol formed from triacylglycerol hydrolysis is converted in two steps to dihydroxyacetone phosphate.

Gluconeogenesis is not a commonly used metabolic pathway when carbohydrate intake is high.

Ketogenesis is the synthesis of ketone bodies from acetyl CoA.

Which quantities need to be considered in determining the ATP yield from the complete catabolism of a fatty acid?

Glucosamine,shown below,is a competitive inhibitor of the enzyme hexokinase,which catalyzes the phosphorylation of glucose in the first step of glycolysis (Eqn. 1 below) . Which statement best describes the inhibition by glucosamine?

How is pyruvate converted to acetyl CoA?

Six of the steps of gluconeogenesis use the same enzymes as used in glycolysis.

When energy demands are low,glucose is stored as the polymer ________ in the liver and muscles.

Which factors increase the rate of gluconeogenesis?

Glycolysis is a cyclic,10-step pathway.

Which statement best describes the energy requirement for the conversion of a fatty acid to a thioester with coenzyme A in the β-oxidation of a fatty acid?

Transamination is the transfer of an amino group from a(n)_to a(n)____,usually α-ketoglutarate.

In fermentation,the six carbon atoms of glucose are converted to three molecules of ethanol.

What are the products formed in the transamination reaction shown?

The breakdown of amino acids forms NH₄⁺,which enters the urea cycle to form urea,and a carbon skeleton that is metabolized to either pyruvate,acetyl CoA,or an intermediate in the citric acid cycle.

In oxidative deamination,glutamate is re-converted to α-ketoglutarate,which can undergo transamination with another molecule of an amino acid and the cycle repeats.

Conceptually,gluconeogenesis is the reverse of glycolysis; that is,two molecules of pyruvate are converted to glucose by a stepwise pathway that passes through all of the same intermediates encountered in glycolysis.

When acetyl CoA levels exceed the capacity of the citric acid cycle,acetyl CoA is converted to ketone bodies.

The reduction of acetaldehyde,shown below,is the last step in the fermentation process. What is the product of the reduction of acetaldehyde?