Cellular respiration primarily occurs in eukaryotic cells (like those in animals, plants, and fungi) within the mitochondria and cytoplasm, while in prokaryotic cells (like bacteria), it happens solely in the cytoplasm.

This process powers nearly every living organism by converting glucose and oxygen into ATP energy, and understanding its cellular homes clarifies why mitochondria are dubbed the "powerhouses." Eukaryotes handle it in stages across two key spots, while prokaryotes keep it simple without organelles.

Eukaryotic Cells

In cells with nuclei—like your muscle cells or leaf cells—respiration kicks off in the cytoplasm with glycolysis, then shifts to the mitochondria for the heavy lifting.

  • Glycolysis breaks glucose into pyruvate right in the cytoplasm, yielding quick ATP without oxygen.
  • Pyruvate then enters mitochondria for the Krebs cycle (matrix) and electron transport chain (inner membrane), cranking out most ATP aerobically.
  • Plants do it identically, fueling photosynthesis counterparts.

Mitochondria's double membrane and cristae folds boost efficiency, like a factory optimized for energy output.

Prokaryotic Cells

Bacteria and archaea, lacking mitochondria, run the full show in their cytoplasm , with electron transport on the plasma membrane.

  • No organelles means a streamlined, oxygen-dependent or not version all in one space.
  • This adaptation lets prokaryotes thrive in diverse spots, from your gut to hot springs.

Quick Stages Breakdown

Stage| Location (Eukaryotes)| Location (Prokaryotes)| Key Output 15
---|---|---|---
Glycolysis| Cytoplasm| Cytoplasm| 2 ATP, pyruvate
Pyruvate Oxidation| Mitochondrial matrix| Cytoplasm| Acetyl-CoA
Krebs Cycle| Mitochondrial matrix| Cytoplasm| 2 ATP, electron carriers
Electron Transport Chain| Inner mitochondrial membrane| Plasma membrane| ~32 ATP, water

TL;DR: Eukaryotes (most complex life) use cytoplasm + mitochondria; prokaryotes (simple microbes) stick to cytoplasm—both for ATP magic.

Information gathered from public forums or data available on the internet and portrayed here.