Glucose labeled with 14C in C-1 and C-6 gives rise in glycolysis to pyruvate labeled in:

A) A and C. B) all three carbons. C) its carbonyl carbon. D) its carboxyl carbon. E) its methyl carbon. A) A and C. B) all three carbons. C) its carbonyl carbon. D) its carboxyl carbon. E) its methyl carbon.

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

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.

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Question 1

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The 3-phosphoglycerate derived from glucose by glycolysis is formed from glyceraldehyde 3-phosphate.The action of aldolase on fructose 1,6-bisphosphate produces dihydroxyacetone phosphate (derived from C-1,C-2,and C-3 of glucose)and glyceraldehyde 3-phosphate (derived from C-4,C-5,and C-6 of glucose).When triose phosphate isomerase then converts dihydroxyacetone phosphate to glyceraldehyde 3-phosphate,C-3 of glyceraldehyde 3-phosphate will contain both C-1 and C-6 from glucose.

Explain with words,diagrams,or structures why lactate accumulates in the blood during bursts of very vigorous exercise (such as a 100-meter dash).

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During vigorous exercise,the cardiovascular system cannot deliver O₂ to the muscle tissue fast enough to maintain aerobic conditions.As glycolysis proceeds under anaerobic conditions,NAD⁺ is converted to NADH (during the glyceraldehyde 3-phosphate dehydrogenase reaction),but the muscle tissue has no O₂ to which NADH can pass electrons.To recycle NADH to NAD⁺,which is essential for continuing glycolysis,electrons from NADH are used to reduce pyruvate to lactate.

Which of the following reactions in glycolysis utilizes a covalent enzyme intermediate?

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Question 3

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The oxidation of 3 mol of glucose by the pentose phosphate pathway may result in the production of:

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Question 4

In the conversion of glucose to pyruvate via glycolysis,all of the following enzymes participate.Indicate the order in which they function by numbering them. hexokinase _ triose phosphate isomerase _ phosphohexose isomerase _ enolase _ glyceraldehyde 3-phosphate dehydrogenase _ pyruvate kinase _ phosphofructokinase-1 Which of the enzymes represents a major regulation point in glycolysis? Which catalyzes a reaction in which ATP is produced? Which catalyzes a reaction in which NADH is produced?

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Question 5

Galactosemia is a genetic error of metabolism associated with:

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Question 6

In a tissue that metabolizes glucose via the pentose phosphate pathway,C-1 of glucose would be expected to end up principally in:

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Question 7

In humans,gluconeogenesis:

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Question 8

The anaerobic conversion of 1 mol of glucose to 2 mol of lactate by fermentation is accompanied by a net gain of:

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Question 9

Glucose labeled with ¹⁴C in C-1 and C-6 gives rise in glycolysis to pyruvate labeled in:

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Question 10

Draw the structure of 1,3-bisphosphoglycerate.Indicate with an arrow the phosphate ester,and circle the phosphate group for which the free energy of hydrolysis is very high.

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Question 11

In gluconeogenesis,how do animals convert pyruvate to phosphoenolpyruvate? Show structures,enzymes,and cofactors.

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Question 12

At which point in glycolysis do C-3 and C-4 of glucose become chemically equivalent?

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Question 13

When a muscle is stimulated to contract aerobically,less lactic acid is formed than when it contracts anaerobically because:

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Question 14

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:

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Question 15

Briefly describe the possible metabolic fates of pyruvate produced by glycolysis in humans,and explain the circumstances that favor each.

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Question 16

The yeast used in brewing the alcoholic beverage beer can break down glucose either aerobically or anaerobically using alcoholic fermentation.Explain why beer is brewed under anaerobic conditions.

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Question 17

In the alcoholic fermentation of glucose by yeast,thiamine pyrophosphate is a coenzyme required by:

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Question 18

Describe the fate of pyruvate,formed by glycolysis in animal skeletal muscle,under two conditions: (a)at rest,and (b)during an all-out sprint.Show enough detail in your answer to explain why pyruvate metabolism is different in these two cases.

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Question 19

What is gluconeogenesis,and what useful purposes does it serve in people?

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Question 20

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

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.

Explain with words,diagrams,or structures why lactate accumulates in the blood during bursts of very vigorous exercise (such as a 100-meter dash).

Which of the following reactions in glycolysis utilizes a covalent enzyme intermediate?

The oxidation of 3 mol of glucose by the pentose phosphate pathway may result in the production of:

Galactosemia is a genetic error of metabolism associated with:

In a tissue that metabolizes glucose via the pentose phosphate pathway,C-1 of glucose would be expected to end up principally in:

In humans,gluconeogenesis:

The anaerobic conversion of 1 mol of glucose to 2 mol of lactate by fermentation is accompanied by a net gain of:

Glucose labeled with 14C in C-1 and C-6 gives rise in glycolysis to pyruvate labeled in:

Draw the structure of 1,3-bisphosphoglycerate.Indicate with an arrow the phosphate ester,and circle the phosphate group for which the free energy of hydrolysis is very high.

In gluconeogenesis,how do animals convert pyruvate to phosphoenolpyruvate? Show structures,enzymes,and cofactors.

At which point in glycolysis do C-3 and C-4 of glucose become chemically equivalent?

When a muscle is stimulated to contract aerobically,less lactic acid is formed than when it contracts anaerobically because:

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:

Briefly describe the possible metabolic fates of pyruvate produced by glycolysis in humans,and explain the circumstances that favor each.

The yeast used in brewing the alcoholic beverage beer can break down glucose either aerobically or anaerobically using alcoholic fermentation.Explain why beer is brewed under anaerobic conditions.

In the alcoholic fermentation of glucose by yeast,thiamine pyrophosphate is a coenzyme required by:

Describe the fate of pyruvate,formed by glycolysis in animal skeletal muscle,under two conditions: (a)at rest,and (b)during an all-out sprint.Show enough detail in your answer to explain why pyruvate metabolism is different in these two cases.

What is gluconeogenesis,and what useful purposes does it serve in people?

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Glucose labeled with ¹⁴C in C-1 and C-6 gives rise in glycolysis to pyruvate labeled in:

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: