Fermentation does not use oxygen and yields less ATP; cellular respiration uses oxygen and yields more ATP.

It breaks down large molecules into smaller ones, releasing energy.

The mitochondrion.

ATP (adenosine triphosphate).

ATP: Adenosine Triphosphate; ADP: Adenosine Diphosphate.

ATP hydrolysis (energy release).

C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + energy (ATP).

Glycolysis, Citric Acid (Krebs) Cycle, and Electron Transport Chain (ETC).

Pyruvate (pyruvic acid), ATP, and NADH.

Electron Transport Chain.

Glycolysis: Cytoplasm.
Citric Acid (Krebs): Mitochondrial matrix.
Electron Transport Chain: Inner mitochondrial membrane.

Glycolysis: Pyruvate, ATP, NADH.
Krebs Cycle: CO₂, NADH, FADH₂, ATP.
ETC: ATP and H₂O.

Glycolysis: 2 ATP used → 4 ATP made = Net 2 ATP.
Krebs Cycle: 2 ATP (from 2 turns).
ETC: ~28–34 ATP.

Electron carriers that transport high‑energy electrons to the ETC.

About 30–38 ATP per glucose (varies by cell type).

2 ATP per glucose.