[kwot-er-sen-ten-ee-uh l] /ˌkwɒt ər sɛnˈtɛn i əl/
pertaining to or marking a period of 400 years.
[kwot-er-ner-ee, kwuh-tur-nuh-ree] /ˈkwɒt ərˌnɛr i, kwəˈtɜr nə ri/ adjective 1. consisting of four. 2. arranged in fours. 3. (initial capital letter) Geology. noting or pertaining to the present period of earth history, forming the latter part of the Cenozoic Era, originating about 2 million years ago and including the Recent and Pleistocene Epochs. 4. Metallurgy. […]
noun, Biochemistry. 1. the basic structural relationship of the components of a polypeptide, specifically, the type, number, and sequence of amino acids and nucleotides in the chain. quaternary structure The structure that is formed by the joining together of two or more proteins or nucleic acids. The functions of the proteins and nucleic acids are […]
noun, Chemistry. 1. any of a class of salts derived from ammonium in which the nitrogen atom is attached to four organic groups, as in benzalkonium chloride; the salts are cationic surface-active compounds used as antiseptics and disinfectants. noun 1. a type of ionic compound that can be regarded as derived from ammonium compounds by […]
[kwot-er-neyt, kwuh-tur-nit] /ˈkwɒt ərˌneɪt, kwəˈtɜr nɪt/ adjective 1. arranged in or consisting of four parts, as the leaves of certain plants.