What cycle is also known as the citric acid cycle?

The citric acid cycle, also known as the Krebs cycle, is a key metabolic pathway that plays a crucial role in cellular respiration. This cycle occurs in the mitochondria of eukaryotic cells and is essential for converting carbohydrates, fats, and proteins into carbon dioxide and water, while also producing energy in the form of ATP.

The Krebs cycle begins with the formation of citric acid (citrate) when acetyl-CoA combines with oxaloacetate. Throughout the cycle, citrate undergoes several transformations, leading to the release of two molecules of carbon dioxide and the production of reduced electron carriers such as NADH and FADH2. These carriers are vital for the electron transport chain, which generates a significant amount of ATP.

Understanding that the Krebs cycle is integral to aerobic respiration helps clarify its importance in energy metabolism. The other options, such as the Calvin cycle, the light reaction, and glycolysis, refer to different biological processes entirely. The Calvin cycle is involved in photosynthesis, the light reaction refers to the first stage of photosynthesis, and glycolysis is the initial step of glucose metabolism that occurs in the cytoplasm, preceding the Krebs cycle. Recognizing these differentiations highlights the distinct roles each pathway plays in cellular function