| 释义 |
protobiont Biol.|-ˈbaɪɒnt|
[f. Gr. πρωτο- proto- + βιοντ-, pres. pple. stem of βιοῦν to live, f. βίος life.]
A small drop of fluid surrounded by a membrane, hypothesized as ancestral to living cells.
1964A. Synge tr. Oparin's Chem. Origin of Life iii. 61 The droplets would come to contain a constantly increasing concentration of the corresponding catalysts when the mass of the droplet increased as it grew by polymerising the monomers of the surrounding medium. Such coacervate droplets with an improved organisation are still only hypothetical but, for convenience of discussion, we shall refer to them in what follows by the provisional name of ‘protobionts’. 1970A. L. Lehninger Biochem. xxxiv. 782 Oparin..has suggested that the first cells, which he called protobionts, arose when a boundary or membrane formed around one or more macromolecules possessing catalytic activity, presumably proteins. 1971Sci. Amer. May 30/1 Judging from the various forms of life we know today, the first protobionts were probably microscopic in size and single-celled in structure. 1978Ibid. Sept. 65/1 To Oparin the reproductive machinery and DNA are only the ultimate biochemical subtleties that turned metabolically competing protobionts into living cells. |