In cellular respiration, where does the Krebs cycle take place?

The Krebs cycle, also known as the citric acid cycle, occurs in the mitochondrial matrix. This is the innermost compartment of the mitochondria, which is a double-membraned organelle responsible for producing ATP, the energy currency of the cell. The mitochondrial matrix contains enzymes, substrates, and transport molecules necessary for the various reactions that make up the Krebs cycle.

During cellular respiration, pyruvate produced from glycolysis in the cytoplasm is transported into the mitochondria, where it is converted into acetyl-CoA before entering the Krebs cycle. The cycle itself generates key energy-containing molecules, such as NADH and FADH2, which are then used in the electron transport chain to produce ATP.

Understanding this location is crucial because it emphasizes the compartmentalization of cellular processes, highlighting how different metabolic pathways are separated within the cell to optimize function and efficiency.