| Aerobic Respiration | Most efficient form of respiration. | Requires Oxygen | Carbon dioxide and water | Human cells, most organisms |
| Anaerobic Respiration | Occurs in the absence or limited supply of oxygen. | No Oxygen Required | Various end products depending on the pathway (e.g., lactic acid or ethanol) | Yeast, bacteria, muscle cells |
| Lactic Acid Fermentation | Anaerobic process producing lactic acid. | No Oxygen Required | Lactic acid | Muscle cells during intense exercise, some bacteria |
| Alcoholic Fermentation | Anaerobic process producing ethanol and CO2. | No Oxygen Required | Ethanol and carbon dioxide | Yeast (used in brewing and baking), some bacteria |
| Krebs Cycle (Citric Acid Cycle) | Part of aerobic respiration. | Requires Oxygen | Carbon dioxide, ATP, NADH, FADH2 | Mitochondria of eukaryotic cells |
BETA
