Question

During glycolysis, what is the source of the chemical energy that is captured in ATP? A. the chemical bonds in pyruvic acid B. the chemical bonds in glucose C. the nuclei of atoms in glucose D. high-energy electrons in the cytoplasm

Answer 1

During glycolysis, the source of the chemical energy that is captured in ATP:

B. the chemical bonds in glucose

Explanation:

• Glycolysis  is also known as Embden-meyerhof pathway.
• It is an oxidative process in which one mole of glucose is partially oxidized into two moles of pyruvate.
• Glycolysis occurs in the cytosol of the cell in  both aerobic and anaerobic conditions.
• The breakdown of six-carbon glucose into two molecules the three-carbon pyruvate occurs in ten steps.
• The first five steps of this pathway constitute the preparatory phase.This phase consumes energy during the phosphorylation of glucose.
• The preparatory phase produces two molecules of glyceraldehyde 3-phosphate (G3P).
• The  two molecules of G3P are then converted to pyruvate in the next five steps that constitute the payoff phase.

• The energy gain of glycolysis comes in this payoff phase.
• The oxidation of G3P yields a high energy molegule 1,3 -bisphosphoglycerate .
• The high energy phosphate on carbon 1 of this molecule is donated to ADP and ATP is produced.
• This synthesis of ATP is called substrate level phosphorylation because ADP phosphorylation is coupled with exergonic breakdown of a high-energy bond.