Cells that carry out cellular respiration are primarily eukaryotic cell organelles and some prokaryotic processes:
- In most eukaryotes (animals, plants, fungi, and many protists): cellular respiration occurs mainly in the mitochondria. The process begins with glycolysis in the cytoplasm and continues in the mitochondrial matrix and inner membrane to produce ATP via the citric acid cycle and oxidative phosphorylation (electron transport chain). Pyruvate from glycolysis enters mitochondria to fuel these pathways.
- In prokaryotes (bacteria and archaea): since they lack mitochondria, cellular respiration takes place in the cytoplasm and across their plasma membrane. Glycolysis occurs in the cytoplasm, and parts of the oxidative phosphorylation chain are embedded in the plasma membrane.
Key points:
- Glycolysis happens in the cytoplasm for both groups, yielding a small amount of ATP and NADH.
- In eukaryotes, Pyruvate oxidation and the citric acid cycle occur in the mitochondria, generating more NADH and FADH2.
- Oxidative phosphorylation (electron transport chain and ATP synthase) occurs on the inner mitochondrial membrane in eukaryotes, or on the analogous membrane in prokaryotes, producing the majority of ATP.
If you’d like, I can tailor this to a specific organism (e.g., human cells, plant cells) or explain each step (glycolysis, pyruvate oxidation, citric acid cycle, oxidative phosphorylation) in more detail.
