Columbia Encyclopedia

Search results

119 results found

fermentation

(Encyclopedia)fermentation, process by which the living cell is able to obtain energy through the breakdown of glucose and other simple sugar molecules without requiring oxygen. Fermentation is achieved by somewhat...

phosphorylation

(Encyclopedia)phosphorylation, chemical process in which a phosphate group is added to an organic molecule. In living cells phosphorylation is associated with respiration, which takes place in the cell's mitochondr...

aging

(Encyclopedia)aging, in biology, cumulative changes in an organism, organ, tissue, or cell leading to a decrease in functional capacity. In humans, aging is associated with degenerative changes in the skin, bones, ...

blood clotting

(Encyclopedia)blood clotting, process by which the blood coagulates to form solid masses, or clots. In minor injuries, small oval bodies called platelets, or thrombocytes, tend to collect and form plugs in blood ve...

flour

(Encyclopedia)flour, finely ground, usually sifted, meal of grain, such as wheat, rye, corn, rice, or buckwheat. Flour is also made from potatoes, peas, beans, peanuts, etc. Usually it refers to the finely ground a...

HIV

(Encyclopedia)HIV, human immunodeficiency virus, either of two closely related retroviruses that invade T-helper lymphocytes and are responsible for AIDS. There are two types of HIV: HIV-1 and HIV-2. HIV-1 is respo...

flax

(Encyclopedia)flax, common name for members of the Linaceae, a family of annual herbs, especially members of the genus Linum, and for the fiber obtained from such plants. The flax of commerce (several varieties of ...

cysteine

(Encyclopedia)CE5 CE5 cysteine sĭsˈtēn [key], organic compound, one of the 20 amino acids commonly found in animal proteins. Only the l-stereoisomer participates in the biosynthesis of mammalian protein...

meat

(Encyclopedia)meat, term for the flesh of animals used for food, especially that of cattle, sheep, lambs, and swine, as distinct from game, poultry, and fish; sometimes it is inclusive of all animal flesh or of all...

amyotrophic lateral sclerosis

(Encyclopedia)amyotrophic lateral sclerosis (ALS) āˌmīətrōfˈik, sklĭrōˈsĭs [key] or motor neuron disease, sometimes called Lou Gehrig's disease, degenerative disease that affects motor neurons in the brai...