Question 1

Which compound(s) is/are a high-energy intermediate(s) in glycolysis?

Accepted Answer

A)  fructose 1,6-bisphosphate 
B)  NADH 
C)  1,3-bisphosphoglycerate and phosphoenol pyruvate 
D)  fructose 1,6-bisphosphate, 1,3-bisphosphoglycerate, and phosphoenol pyruvate 
E)  NADH, 1,3-bisphosphoglycerate, and phosphoenol pyruvate 
A)  fructose 1,6-bisphosphate 
B)  NADH 
C)  1,3-bisphosphoglycerate and phosphoenol pyruvate 
D)  fructose 1,6-bisphosphate, 1,3-bisphosphoglycerate, and phosphoenol pyruvate 
E)  NADH, 1,3-bisphosphoglycerate, and phosphoenol pyruvate

Question 2

The ultimate electron acceptor in the fermentation of glucose to ethanol is:

Accepted Answer

A)  acetaldehyde. 
B)  acetate. 
C)  ethanol. 
D)  NAD+. 
E)  pyruvate. 
A)  acetaldehyde. 
B)  acetate. 
C)  ethanol. 
D)  NAD+. 
E)  pyruvate.

Question 3

When glucose is oxidized via glycolysis, the carbon atom that bears the phosphate in the 3-phosphoglycerate formed may have originally been either C-1 or C-6 of the original glucose. Describe this pathway in just enough detail to explain this fact.

Accepted Answer

During glycolysis, glucose is oxidized t

Question 4

Which statement does NOT describe a general function of the pentose phosphate pathway?

Accepted Answer

A)  The pentose phosphate pathway is used to produce NADPH for reductive biosynthesis in adipocytes. 
B)  The pentose phosphate pathway is used to facilitate the elimination of dangerous peroxides in erythrocytes. 
C)  The pentose phosphate pathway allows for the entry of dietary pentose intermediates into the glycolytic pathway. 
D)  The pentose phosphate pathway allows for the conversion of hexoses into pentoses that may be used as precursors in the synthesis of nucleosides. 
E)  The pentose phosphate pathway produces reduced molecules whose electrons may be shuttled to the mitochondria for oxidative phosphorylation. 
A)  The pentose phosphate pathway is used to produce NADPH for reductive biosynthesis in adipocytes. 
B)  The pentose phosphate pathway is used to facilitate the elimination of dangerous peroxides in erythrocytes. 
C)  The pentose phosphate pathway allows for the entry of dietary pentose intermediates into the glycolytic pathway. 
D)  The pentose phosphate pathway allows for the conversion of hexoses into pentoses that may be used as precursors in the synthesis of nucleosides. 
E)  The pentose phosphate pathway produces reduced molecules whose electrons may be shuttled to the mitochondria for oxidative phosphorylation.

Question 5

In humans, the Cori cycle shifts part of the metabolic burden of active muscle to the liver. Which two metabolic pathways are involved in this cycle?

Accepted Answer

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

Question 6

In some tissues, an increase in insulin will substantially increase the glucose transporters in the cell membrane and the transport of glucose into cells. Which tissues react in this manner?

Accepted Answer

A)  red blood cells and the brain 
B)  the brain and the liver 
C)  the liver and muscle 
D)  muscle and adipose tissue 
E)  adipose tissue and red blood cells 
A)  red blood cells and the brain 
B)  the brain and the liver 
C)  the liver and muscle 
D)  muscle and adipose tissue 
E)  adipose tissue and red blood cells

Question 7

During strenuous exercise, the NADH formed in the glyceraldehyde 3-phosphate dehydrogenase reaction in skeletal muscle must be reoxidized to NAD+ if glycolysis is to continue. The most important reaction involved in the reoxidation of NADH is:

Accepted Answer

A)  dihydroxyacetone phosphate $\rightarrow$  glycerol 3-phosphate. 
B)  glucose 6-phosphate $\rightarrow$  fructose 6-phosphate. 
C)  isocitrate $\rightarrow$ $\alpha$-ketoglutarate. 
D)  oxaloacetate $\rightarrow$  malate. 
E)  pyruvate $\rightarrow$  lactate. 
A)  dihydroxyacetone phosphate $\rightarrow$  glycerol 3-phosphate. 
B)  glucose 6-phosphate $\rightarrow$  fructose 6-phosphate. 
C)  isocitrate $\rightarrow$ $\alpha$-ketoglutarate. 
D)  oxaloacetate $\rightarrow$  malate. 
E)  pyruvate $\rightarrow$  lactate.

Question 8

Which reaction does NOT convert gluconeogenic precursors to the next step in gluconeogenesis?

Accepted Answer

A)  Glycerol is converted to dihydroxyacetone phosphate using the enzymes glycerol kinase and glycerol-3-phosphate dehydrogenase. 
B)  Lactate is converted to alanine using lactate dehydrogenase. 
C)  Alanine is converted to pyruvate using alanine aminotransferase. 
D)  Glutamate is converted to $\alpha$-ketoglutarate using either glutamate dehydrogenase or an aminotransferase. 
E)  Pyruvate is carboxylated using bicarbonate and pyruvate carboxylase. 
A)  Glycerol is converted to dihydroxyacetone phosphate using the enzymes glycerol kinase and glycerol-3-phosphate dehydrogenase. 
B)  Lactate is converted to alanine using lactate dehydrogenase. 
C)  Alanine is converted to pyruvate using alanine aminotransferase. 
D)  Glutamate is converted to $\alpha$-ketoglutarate using either glutamate dehydrogenase or an aminotransferase. 
E)  Pyruvate is carboxylated using bicarbonate and pyruvate carboxylase.

Question 9

Which reaction in glycolysis utilizes a covalent enzyme intermediate?

Accepted Answer

A)  phosphofructokinase-1 
B)  glyceraldehyde-3-phosphate dehydrogenase 
C)  phosphohexose isomerase 
D)  enolase 
E)  triose phosphate isomerase 
A)  phosphofructokinase-1 
B)  glyceraldehyde-3-phosphate dehydrogenase 
C)  phosphohexose isomerase 
D)  enolase 
E)  triose phosphate isomerase

Question 10

Which statement about the pentose phosphate pathway is INCORRECT?

Accepted Answer

A)  It generates CO2 from C-1 of glucose. 
B)  It involves the conversion of an aldohexose to an aldopentose. 
C)  It is prominant in lactating mammary gland. 
D)  It is principally directed toward the generation of NADPH. 
E)  It requires the participation of molecular oxygen. 
A)  It generates CO2 from C-1 of glucose. 
B)  It involves the conversion of an aldohexose to an aldopentose. 
C)  It is prominant in lactating mammary gland. 
D)  It is principally directed toward the generation of NADPH. 
E)  It requires the participation of molecular oxygen.

Question 11

In the Cori Cycle, actively contracting muscle cells convert pyruvate to lactate. The lactate is transported in the blood to the liver, where it is "recycled" by gluconeogenesis to glucose, which is transported back to the muscle for additional ATP production. Why do active muscle cells simply not export pyruvate, which can also be converted in the liver to glucose?

Accepted Answer

Active muscle cells do not simply export

Question 12

Which compound CANNOT serve as the starting material for the synthesis of glucose via gluconeogenesis?

Accepted Answer

A)  acetate 
B)  glycerol 
C)  lactate 
D)  oxaloacetate 
E)  $\alpha$-ketoglutarate 
A)  acetate 
B)  glycerol 
C)  lactate 
D)  oxaloacetate 
E)  $\alpha$-ketoglutarate

Which compound(s) is/are a high-energy intermediate(s) in glycolysis?

The ultimate electron acceptor in the fermentation of glucose to ethanol is:

When glucose is oxidized via glycolysis, the carbon atom that bears the phosphate in the 3-phosphoglycerate formed may have originally been either C-1 or C-6 of the original glucose. Describe this pathway in just enough detail to explain this fact.

Which statement does NOT describe a general function of the pentose phosphate pathway?

In humans, the Cori cycle shifts part of the metabolic burden of active muscle to the liver. Which two metabolic pathways are involved in this cycle?

In some tissues, an increase in insulin will substantially increase the glucose transporters in the cell membrane and the transport of glucose into cells. Which tissues react in this manner?

During strenuous exercise, the NADH formed in the glyceraldehyde 3-phosphate dehydrogenase reaction in skeletal muscle must be reoxidized to NAD⁺ if glycolysis is to continue. The most important reaction involved in the reoxidation of NADH is:

Which reaction does NOT convert gluconeogenic precursors to the next step in gluconeogenesis?

Which reaction in glycolysis utilizes a covalent enzyme intermediate?

Which statement about the pentose phosphate pathway is INCORRECT?

Which compound CANNOT serve as the starting material for the synthesis of glucose via gluconeogenesis?

The Foundations of Biochemistry

Water

Amino Acids, Peptides, and Proteins

The Three-Dimensional Structure of Proteins

Protein Function

Enzymes

Carbohydrates and Glycobiology

Nucleotides and Nucleic Acids

DNA-Based Information Technologies

Lipids

Biological Membranes and Transport

Biosignaling

Bioenergetics and Biochemical Reaction Types

Principles of Metabolic Regulation

The Citric Acid Cycle

Fatty Acid Catabolism

Amino Acid Oxidation and the Production of Urea

Oxidative Phosphorylation and Photophosphorylation

Carbohydrate Biosynthesis in Plants and Bacteria

Lipid Biosynthesis

Biosynthesis of Amino Acids, Nucleotides, and Related Molecules

Hormonal Regulation and Integration of Mammalian Metabolism

Genes and Chromosomes

DNA Metabolism

RNA Metabolism

Protein Metabolism

Regulation of Gene Expression

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Exam 14: Glycolysis, Gluconeogenesis, and the Pentose Phosphate Pathway

Which compound(s) is/are a high-energy intermediate(s) in glycolysis?

The ultimate electron acceptor in the fermentation of glucose to ethanol is:

When glucose is oxidized via glycolysis, the carbon atom that bears the phosphate in the 3-phosphoglycerate formed may have originally been either C-1 or C-6 of the original glucose. Describe this pathway in just enough detail to explain this fact.

Which statement does NOT describe a general function of the pentose phosphate pathway?

In humans, the Cori cycle shifts part of the metabolic burden of active muscle to the liver. Which two metabolic pathways are involved in this cycle?

In some tissues, an increase in insulin will substantially increase the glucose transporters in the cell membrane and the transport of glucose into cells. Which tissues react in this manner?

During strenuous exercise, the NADH formed in the glyceraldehyde 3-phosphate dehydrogenase reaction in skeletal muscle must be reoxidized to NAD+ if glycolysis is to continue. The most important reaction involved in the reoxidation of NADH is:

Which reaction does NOT convert gluconeogenic precursors to the next step in gluconeogenesis?

Which reaction in glycolysis utilizes a covalent enzyme intermediate?

Which statement about the pentose phosphate pathway is INCORRECT?

Which compound CANNOT serve as the starting material for the synthesis of glucose via gluconeogenesis?

The Foundations of Biochemistry

Water

Amino Acids, Peptides, and Proteins

The Three-Dimensional Structure of Proteins

Protein Function

Enzymes

Carbohydrates and Glycobiology

Nucleotides and Nucleic Acids

DNA-Based Information Technologies

Lipids

Biological Membranes and Transport

Biosignaling

Bioenergetics and Biochemical Reaction Types

Principles of Metabolic Regulation

The Citric Acid Cycle

Fatty Acid Catabolism

Amino Acid Oxidation and the Production of Urea

Oxidative Phosphorylation and Photophosphorylation

Carbohydrate Biosynthesis in Plants and Bacteria

Lipid Biosynthesis

Biosynthesis of Amino Acids, Nucleotides, and Related Molecules

Hormonal Regulation and Integration of Mammalian Metabolism

Genes and Chromosomes

DNA Metabolism

RNA Metabolism

Protein Metabolism

Regulation of Gene Expression

Filters

During strenuous exercise, the NADH formed in the glyceraldehyde 3-phosphate dehydrogenase reaction in skeletal muscle must be reoxidized to NAD⁺ if glycolysis is to continue. The most important reaction involved in the reoxidation of NADH is: