What is the energy output of reaction 7 of glycolysis (1,3-bisphosphoglycerate to 3-phosphoglycerate)?

• A. 2 ATP
• B. 2 NADH
• C. 1 ATP
• D. 1 NADH and 1 FADH₂

Answer: (A)

Verified step by step guidance

1. Understand the context of glycolysis: Glycolysis is a metabolic pathway that converts glucose into pyruvate, releasing energy in the form of ATP and NADH. Reaction 7 specifically involves the conversion of 1,3-bisphosphoglycerate to 3-phosphoglycerate.
2. Identify the type of reaction: Reaction 7 is a substrate-level phosphorylation, where a phosphate group is transferred from 1,3-bisphosphoglycerate to ADP, forming ATP.
3. Recognize the products of the reaction: The conversion of 1,3-bisphosphoglycerate to 3-phosphoglycerate results in the production of ATP. This is a key step in glycolysis where energy is directly generated.
4. Consider the stoichiometry of glycolysis: Glycolysis involves the breakdown of one glucose molecule into two pyruvate molecules, meaning each step occurs twice per glucose molecule. Therefore, the energy output from reaction 7 is doubled.
5. Evaluate the options given: Based on the understanding of glycolysis and reaction 7, determine which option correctly represents the energy output in terms of ATP and NADH production.