Biochemistry : Reactants and Products of Glycolysis

Study concepts, example questions & explanations for Biochemistry

varsity tutors app store varsity tutors android store

Example Questions

Example Question #41 : Glycolysis

Which process involved in cellular respiration does not yield any high energy phosphate bonds?

Possible Answers:

All of these produce new high energy phosphate bonds

Glycolysis

Krebs cycle

Electron transport chain/ATP synthase

Pyruvate dehydrogenase complex

Correct answer:

Pyruvate dehydrogenase complex

Explanation:

Glycolysis has a net yield of 2 ATP per glucose molecules. The Krebs cycle produces 2 GTP molecules per glucose. The electron transport chain and ATP synthase are the main producers of ATP in cellular respiration. The pyruvate dehydrogenase complex, however, does not yield any ATP (or any other nucleoside phosphates). It simply produces acetyl-CoA from pyruvate, releasing one molecule of carbon dioxide per pyruvate.

Example Question #41 : Glycolysis

What enzymes in the glycolysis pathway in the liver catalyze irreversible reactions?

Possible Answers:

Glucokinase, pyruvate kinase, enolase

Glucokinase, phosphoglycerate kinase, mutase

Glucokinase, phosphofructokinase-1, pyruvate kinase

Aldolase, phosphofructokinase-1, mutase

Isomerase, aldolase, mutase

Correct answer:

Glucokinase, phosphofructokinase-1, pyruvate kinase

Explanation:

In the liver, glucokinase irreversibly converts glucose in the cell to glucose-6-phosphate. Phosphofructose kinase-1 irreversibly converts fructose-6-phosphate to fructose-1,6-bisphosphate. Pyruvate kinase converts phosphoenolpyruvate to pyruvate. All the other enzymes listed catalyze reversible glycolysis reactions.

Learning Tools by Varsity Tutors