Here's a breakdown of the key steps:
1. Glycolysis: This occurs in the cytoplasm and breaks down glucose into two molecules of pyruvate. It produces a small amount of ATP (the cell's energy currency) and NADH (an electron carrier).
2. Pyruvate Oxidation: Pyruvate moves into the mitochondria and is converted into acetyl-CoA. This step also produces NADH.
3. Krebs Cycle (Citric Acid Cycle): Acetyl-CoA enters the Krebs cycle, which generates more ATP, NADH, and FADH2 (another electron carrier).
4. Electron Transport Chain: The NADH and FADH2 deliver electrons to the electron transport chain, a series of protein complexes embedded in the mitochondrial membrane. As electrons move through the chain, a proton gradient is established across the membrane.
5. Oxidative Phosphorylation: The proton gradient drives ATP synthesis by ATP synthase, a protein complex that uses the flow of protons to generate ATP. This is the primary way cells produce ATP from glucose.
Cellular respiration is an essential process for all living organisms. It allows cells to extract energy from glucose and use it to perform vital functions, such as growth, movement, and maintaining internal balance.
