Question

Which electron carrier(s) function in the citric acid cycle?

Answer 1

In the citric acid cycle, NAD+ and FAD serve as electron carriers, being reduced to NADH and FADH₂, which transport electrons to the electron transport chain. The cycle produces three NADH, one FADH₂, and one ATP or GTP per acetyl-CoA molecule.

Step-by-step explanation:

The citric acid cycle, also known as the Krebs cycle, is a critical metabolic pathway that operates in the mitochondrial matrix. In this cycle, electron carriers such as NAD+ and FAD are reduced to NADH and FADH₂, respectively. These carriers then transport electrons to the electron transport chain for further processing and energy production.

During the citric acid cycle, each acetyl-CoA molecule that enters the cycle contributes to the formation of three NADH, one FADH₂, and one ATP or GTP (depending on the cell type). Carbon dioxide is also produced and released as a waste product.

The cycle begins when the acetyl group from acetyl CoA combines with oxaloacetate to form citrate. After several steps of oxidation and decarboxylation, the oxaloacetate is regenerated, allowing the cycle to run continuously as long as reactants are present.

Answer 2

NADH and FADH2 are the electron carriers which contain most of the energy extracted from Glucose, the original energy source. This energy was the result during the processes of glycolysis and the citric acid cycle. In short, most of the energy in a cell flows from Glucose to NADH, to the electron transport chain to a proton-motive force to Adenosine Triposphate (ATP).