* Mitochondria: This is the powerhouse of the cell. It's where the majority of ATP is produced through cellular respiration. The following processes happen within the mitochondria:
* Krebs cycle (citric acid cycle): This cycle breaks down pyruvate (a product of glucose breakdown) to generate electron carriers (NADH and FADH2).
* Electron transport chain: This series of protein complexes uses the electrons from NADH and FADH2 to pump protons across the inner mitochondrial membrane, creating a proton gradient. This gradient is then used to drive the production of ATP by ATP synthase.
* Cytoplasm: While not an organelle itself, the cytoplasm contains enzymes that catalyze the initial steps of glucose breakdown:
* Glycolysis: This process breaks down glucose into pyruvate, generating a small amount of ATP and NADH.
Note: While the mitochondria are the primary site of ATP production, glycolysis occurs in the cytoplasm, and it provides the initial steps for glucose breakdown and the starting material for the Krebs cycle.
