What are the main outputs of the Krebs cycle?

The Krebs cycle, also known as the citric acid cycle or TCA cycle, is a crucial part of cellular respiration that occurs in the mitochondria. Its main outputs are NADH, FADH2, ATP (or GTP), and carbon dioxide.

During the cycle, each acetyl-CoA molecule that enters the Krebs cycle is oxidized through a series of enzymatic reactions. This oxidation reduces NAD+ to NADH and FAD to FADH2, capturing high-energy electrons that are later used in the electron transport chain to produce ATP. Additionally, the cycle generates ATP (or GTP), which is a direct energy currency for the cell.

As a byproduct of these reactions, carbon dioxide is produced, which is then expelled from the cell and ultimately from the organism's body during respiration. This sum of outputs reflects the cycle's role in breaking down organic molecules to extract usable energy and reducing equivalents, essential for sustaining life processes.

The other options do not accurately represent the outputs of the Krebs cycle. Water and glucose, for instance, are associated with different metabolic pathways, while oxygen and lactic acid, as well as carbon dioxide and ethyl alcohol, relate to anaerobic processes or fermentation rather than the