| 释义 |
cytochrome|ˈsaɪtəʊkrəʊm|
[f. cyto- + Gr. χρῶµα colour.]
1. (See quot.)
1900Dorland Med. Dict., Cytochrome, a nerve-cell having an ill-developed cell-body, in which the stained nucleus appears to be completely surrounded, and does not exceed in size the nucleus of a neuroglia-cell or a leukocyte.
2. Any of several closely related compounds, present in the cells of most aerobic organisms, which play an important part in cell respiration and consist of an iron-containing porphyrin attached to a protein; together they constitute the cytochrome system.
1925D. Keilin in Proc. R. Soc. B. XCVIII. 314 There is ample evidence that this pigment is not a simple compound, but a complex formed of three distinct haemochromogen compounds, the nature of which is not yet completely elucidated. I propose therefore to describe it under the name of Cytochrome, signifying merely ‘cellular pigment’. 1948New Biol. V. 126 Oxygen of the atmosphere enters the metabolism of the cell by combining with cytochrome, which then hands it on to other substances. 1953Fruton & Simmonds Gen. Biochem. xiv. 339 Cytochrome a1 and a2 were observed spectroscopically in certain bacteria that lack cytochrome a. 1957Endeavour Oct. 196/1 [Lundegårdh's] suggestion..was that the cytochrome system, which carries electrons from the substrates of the respiration system to molecular oxygen at the surface of the cell, might function as a carrier of anions towards the centre of the cell. 1965Bell & Coombe tr. Strasburger's Textbk. Bot. (new ed.) ii. i. 282 An electron is transferred from the hydrogen to the cytochrome c, making its trivalent iron again divalent. 1969Times 29 Apr. 13/1 Human cytochrome C is identical to the equivalent molecule in chimpanzees in all of its 104 units. 1970Ambrose & Easty Cell Biol. vii. 228 Chlorophyll, haemoglobin, and the cytochromes all contain a common cyclic structure, called a porphyrin. 1970New Scientist 16 July 119/1 Cytochrome c is a key molecule in the final stages of the ‘burning’ of foodstuffs for the provision of energy in living cells. |
