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thyroxine

(Encyclopedia)thyroxine thīrŏkˈsēn [key], substance secreted by the thyroid gland. The hormone thyroxine forms by combining the amino acid tyrosine with iodine. Complexed to a protein, it is stored in the folli...

Ramakrishnan, Venkatraman

(Encyclopedia)Ramakrishnan, Venkatraman, 1952–, American molecular biologist, b. India, Ph.D. Ohio Univ., 1976. He was a researcher at Oak Ridge National Laboratory (1982–83) and at Brookhaven National Laborato...

skin

(Encyclopedia)CE5 Cross section of skin skin, the flexible tissue (integument) enclosing the body of vertebrate animals. In humans and other mammals, the skin operates a complex organ of numerous structures (so...

micromechanics

(Encyclopedia)micromechanics, the combination of minuscule electrical and mechanical components in a single device less than 1 mm across, such as a valve or a motor. Although micromechanical production processes an...

giraffe

(Encyclopedia)giraffe, African ruminant mammal, genus Giraffa, living in open savanna S of the Sahara. Giraffes have historically been considered to be one species, G. camelopardalis, with a number of subspecies, b...

antioxidant

(Encyclopedia)antioxidant, substance that prevents or slows the breakdown of another substance by oxygen. Synthetic and natural antioxidants are used to slow the deterioration of gasoline and rubber, and such antio...

interferon

(Encyclopedia)interferon ĭnˌtərfērˈŏn [key], any of a group of proteins produced by cells in the body in response to an attack by a virus. A cell infected by a virus releases minute amounts of interferons, wh...

Darwin's finches

(Encyclopedia)Darwin's finches or Galapagos finches gəläˈpəgōsˌ [key], species of small perching birds, constituting the subfamily Geospizinae of the tanager family. Not related to the true finches, this grou...

pharming

(Encyclopedia)pharming färˈmĭng [key], the use of genetically altered livestock, such as cows, goats, pigs, and chickens, to produce medically useful products. In pharming, researchers first create hybrid genes ...

bacteria

(Encyclopedia)bacteria [pl. of bacterium], microscopic unicellular prokaryotic organisms characterized by the lack of a membrane-bound nucleus and membrane-bound organelles. Once considered a part of the plant king...