what are the three stages of cellular respiration?

The three main stages of cellular respiration are glycolysis , the Krebs (citric acid) cycle , and the electron transport chain.

Quick Scoop

• Glycolysis :
  • Happens in the cytoplasm.
  • Breaks one glucose molecule into two pyruvate molecules, producing a small amount of ATP and NADH.
• Krebs (Citric Acid) Cycle :
  • Takes place in the mitochondrial matrix.
  • Uses acetyl-CoA (from pyruvate) to release carbon dioxide and generate high‑energy electron carriers (NADH, FADH₂) and a bit of ATP.
• Electron Transport Chain (ETC) :
  • Located on the inner mitochondrial membrane.
  • Uses electrons from NADH and FADH₂ to power a series of reactions that pump protons and drive the production of most of the ATP in cellular respiration.

Put simply: glycolysis starts breaking down glucose, the Krebs cycle harvests more energy-rich electrons, and the electron transport chain cashes those electrons in for lots of ATP.