Biochemistry
Anaerobic
Not requiring or occurring in the absence of oxygen. Anaerobic metabolism is less efficient but allows life in oxygen-free environments.
Biological Context
Anaerobic bacteria dominate oxygen-free environments like deep sediments, the gut, and waterlogged soils. Fermentation is anaerobic metabolism. When muscles work faster than oxygen can be delivered, they switch to anaerobic metabolism, producing lactic acid.