Fermentation

Abstract

Respiration is the release of energy in living organisms. Fermentation is respiration with a waste product other than carbon dioxide and water. Fermentation is common in microorganisms. Its waste products vary greatly but always include at least one complex chemical compound such as lactic acid or ethanol (alcohol). You do not need to remember them, but the chemical formula of lactic acid is CH₃CHOHCOOH and of ethanol is CH₃CH₂OH. Humans have found uses for only a few of the complex compounds that are waste products of fermentation. Ethanol (alcohol) is one you will have recognised. To produce such compounds industrially, humans make use of microorganisms. Scientists have been able to extract some of the enzymes used in fermentations from the microorganisms that make them. Some industrial fermentations use only extracted enzymes, not whole microorganisms.