Question

Summarize what happens during the Krebs cycle. What happens to high-energy electrons generated during the Krebs cycle?

a) The Krebs cycle produces ATP; high-energy electrons are used to reduce oxygen.
b) The Krebs cycle produces glucose; high-energy electrons are used for cell division.
c) The Krebs cycle produces pyruvate; high-energy electrons are stored in NADH and FADH2.
d) The Krebs cycle produces amino acids; high-energy electrons are released as heat.

Answer 1

During the Krebs cycle, pyruvate from glycolysis is converted to acetyl CoA, which produces CO2, NADH, FADH2, and ATP. The high-energy electrons from NADH and FADH2 are then used in oxidative phosphorylation to produce ATP, with oxygen as the final electron acceptor.

Step-by-step explanation:

Krebs Cycle Summary

The Krebs cycle, also known as the citric acid cycle or tricarboxylic acid (TCA) cycle, is a key metabolic pathway involved in cellular respiration. It takes place in the matrix of the mitochondrion following glycolysis. During the Krebs cycle, the pyruvate produced from glycolysis is transformed into two-carbon acetyl coenzyme A (acetyl CoA) molecules. When acetyl CoA enters the Krebs cycle, it is processed through a series of reactions that result in the release of CO2, the reduction of electron carriers NAD+ to NADH, and FAD to FADH2, and the synthesis of ATP. The high-energy electrons stored in NADH and FADH2 are later used in the electron transport chain to produce a significant amount of ATP during oxidative phosphorylation.

To address the specific question, the correct answer is (a) The Krebs cycle produces ATP; high-energy electrons are used to reduce oxygen. This implies that the high-energy electrons generated during the Krebs cycle are subsequently used by the electron transport chain to create a proton gradient across the inner mitochondrial membrane, ultimately leading to the production of ATP through oxidative phosphorylation.