Columbia Encyclopedia

Search results

500 results found

triglyceride

(Encyclopedia)triglyceride, ester formed from glycerol and one to three fatty acids. Fats and oils are triglycerides. In a simple triglyceride such as palmitin or stearin, all three fatty-acid groups are identical....

sepal

(Encyclopedia)sepal, a modified leaf, part of the outermost of the four groups of flower parts. The sepals of a flower are collectively called the calyx and act as a protective covering of the inner flower parts in...

Alzheimer's disease

(Encyclopedia)Alzheimer's disease ălsˈhīˌmərz, ôls– [key], degenerative disease of nerve cells in the cerebral cortex that leads to atrophy of the brain and senile dementia and, ultimately, death. The disea...

Krebs cycle

(Encyclopedia)Krebs cycle, series of chemical reactions carried out in the living cell; in most higher animals, including humans, it is essential for the oxidative metabolism of glucose and other simple sugars. The...

Tuareg

(Encyclopedia)Tuareg or Touareg both: twäˈrĕg [key], Berbers of the Sahara, numbering c.2 million. They have preserved their ancient alphabet, which is related to that used by ancient Libyans. The Tuaregs tradit...

diathermy

(Encyclopedia)diathermy dīˈəthûrˌmē [key], therapeutic measure used in medicine to generate heat in the body tissues. Electrodes and other instruments are used to transmit electric current to surface structur...

fiber, dietary

(Encyclopedia)fiber, dietary, bulky part of food that cannot be broken down by enzymes in the small intestine of the digestive system. Almost all natural fiber comes from plants. Although fiber has little nutrition...

erysipelas

(Encyclopedia)erysipelas ĕrəsĭpˈələs [key], acute infection of the skin characterized by a sharply demarcated, shiny red swelling, accompanied by high fever and a feeling of general illness. The causative age...

athlete's heart

(Encyclopedia)athlete's heart, common term for an enlarged heart associated with repeated strenuous exercise. As a result of the increased workload required of it, the heart will increase physiologically by enlargi...

Kendrew, John Cowdery

(Encyclopedia)Kendrew, John Cowdery, 1917–97, British biochemist, grad. Cambridge (Ph.D. 1949). He was a fellow of Peterhouse College at Cambridge from 1947 to 1975 and was scientific adviser to the British minis...