Columbia Encyclopedia

Search results

159 results found

mucopolysaccharide

(Encyclopedia)mucopolysaccharide myo͞oˌkəpŏlēsăkˈərīd [key], class of polysaccharide molecules, also known as glycosaminoglycans, composed of amino-sugars chemically linked into repeating units that give a...

Le Châtelier's principle

(Encyclopedia)Le Châtelier's principle, chemical principle that states that if a system in equilibrium is disturbed by changes in determining factors, such as temperature, pressure, and concentration of components...

Liebig, Justus, Baron von

(Encyclopedia)Liebig, Justus, Baron von yo͝osˈto͝os bärônˈ fən lēˈbĭkh [key], 1803–73, German chemist. As professor at Giessen (1824–52), he was among the first to establish a chemical teaching labora...

mass number

(Encyclopedia)mass number, often represented by the symbol A, the total number of nucleons (neutrons and protons) in the nucleus of an atom. All atoms of a chemical element have the same atomic number (number of pr...

Urey, Harold Clayton

(Encyclopedia)Urey, Harold Clayton yo͝orˈē [key], 1893–1981, American chemist, b. Walkerton, Ind., grad. Univ. of Montana (B.S., 1917), Ph.D. Univ. of California, 1923. He taught at Johns Hopkins (1924–29), ...

Jovian planets

(Encyclopedia)Jovian planets, the planets Jupiter, Saturn, Uranus, and Neptune. They are all larger and more massive than the earth. Since they rotate faster, they are more flattened at the poles than are the terre...

furnace

(Encyclopedia)furnace, enclosed space for the burning of fuel. There are many kinds of furnaces, the type depending upon the fuel and the use to which the heat produced within it is put. Most familiar are the furna...

autotroph

(Encyclopedia)autotroph ôtˈətrōfˌ [key], in biology, an organism capable of synthesizing its own organic substances from inorganic compounds. Autotrophs produce their own sugars, lipids, and amino acids using ...

Crutzen, Paul Jozef

(Encyclopedia)Crutzen, Paul Jozef, 1933–2021, Dutch atmospheric chemist, grad. Univ. of Stockholm (Ph.D. 1968, D.Sc. 1973). After working (1977–80) for the Nation...

uremia

(Encyclopedia)uremia yo͝orēˈmēə [key], condition resulting from advanced stages of kidney failure in which urea and other nitrogen-containing wastes are found in the blood. Uremia can be caused by NSAIDs (nons...