Columbia Encyclopedia

Search results

119 results found

aldosterone

(Encyclopedia)aldosterone ălˌdōstĭrōnˈ [key], steroid secreted by the cortex of the adrenal gland. It is the most potent hormone regulating the body's electrolyte balance. Aldosterone acts directly on the kid...

methotrexate

(Encyclopedia)methotrexate, drug used in halting the growth of actively proliferating tissues. Introduced in the 1950s, it is used in the treatment of leukemia, psoriasis, and non-Hodgkin's lymphoma. By binding to ...

trypsin

(Encyclopedia)trypsin, enzyme that acts to degrade protein; it is often referred to as a proteolytic enzyme, or proteinase. Trypsin is one of the three principal digestive proteinases, the other two being pepsin an...

lactose

(Encyclopedia)lactose lăkˈtōs [key] or milk sugar, white crystalline disaccharide (see carbohydrate). It has the same empirical formula (C12H22O11) as sucrose (cane sugar) and maltose but differs from both in st...

ethanol

(Encyclopedia)ethanol ĕthˈənōlˌ [key] or ethyl alcohol, CH3CH2OH, a colorless liquid with characteristic odor and taste; commonly called grain alcohol or simply alcohol. Ethanol is used extensively as a solv...

Tay-Sachs disease

(Encyclopedia)Tay-Sachs disease tāˈ-săksˈ [key], rare hereditary disease caused by a genetic mutation that leaves the body unable to produce an enzyme necessary for fat metabolism in nerve cells, producing cent...

malt

(Encyclopedia)malt, a grain (usually barley) steeped in water, partially germinated, then dried and cured. It is used in brewing to convert cereal starches to sugars by means of the enzymes (chiefly diastase) produ...

Buchner, Eduard

(Encyclopedia)Buchner, Eduard āˈdo͞oärt bo͞okhˈnər [key], 1860–1917, German chemist. He taught at Berlin, Breslau, and, from 1911, at Würzburg. He discovered (1896) that alcoholic fermentation of sugars i...

Takamine, Jokichi

(Encyclopedia)Takamine, Jokichi jōˈkēchē täkäˈmĭnāˌ [key], 1854–1922, Japanese chemist. He served (1881–84) as chemist in the employ of the Japanese government and (1887) organized a fertilizer manufa...

denaturation

(Encyclopedia)denaturation, term used to describe the loss of native, higher-order structure of protein molecules in solution. Most globular proteins exhibit complicated three-dimensional folding described as secon...