What cell performs anaerobic respiration?

Anaerobic respiration occurs in both prokaryotic and eukaryotic cells. In both types of cells, sugar is broken down to generate energy without the use of oxygen gas. For example, prokaryotic archaea, such as methanogens, reduce carbon dioxide to methane in order to oxidize NADH. These microorganisms are able to survive in low oxygen or oxygen-less environments due to their ability to respire anaerobically. Eukaryotic cells may also utilize anaerobic respiration when their oxygen levels fall. For example, when muscle cells exhaust their oxygen supply following heavy exercise, they use lactic acid fermentation to provide ATP for energy. During this process, each molecule of pyruvate is converted into lactic acid. 4 NAD+ is subsequently produced, in which 2 of them return to the glycolysis pathway.