| 释义 |
phosphatase Biochem.|ˈfɒsfəteɪz, -s|
[f. phosphate + -ase.]
a. Any enzyme which catalyses the synthesis or hydrolysis of an ester of phosphoric acid.
H. Euler (in Zeitschr. für physiol. Chem. (1911) LXXVII. 14) coined the G. phosphatese, having proposed that the termination -ase be restricted to enzymes which decompose substrates, and -ese be used for enzymes which synthesize. Hence quot. 1911.
[1911Jrnl. Chem. Soc. C. i. 1051 There is no evidence that the enzyme which synthesises carbohydrate phosphoric acid esters has any splitting action. The term phosphatese is suggested.] 1912Chem. Abstr. VI. 2084 Expts. with pepsin, trypsin, and animal organ exts. failed to show conclusively the presence of phosphatase. 1931Times Lit. Suppl. 2 Apr. 274/3 There are two mechanisms at work in calcification: (a) a phosphatase mechanism which produces in the matrix fluid, by hydrolysis of phosphoric ester, a condition of supersaturation with respect to the bone phosphate. 1951West & Todd Textbk. Biochem. xiv. 471 The acid and the alkaline phosphatases of serum are so called because of optimum activity at an acid and at an alkaline pH respectively. 1968[see isoenzyme]. 1973B. J. Williams Evolution & Human Origins iv. 67/1 Red cell acid phosphatase provides a good illustration of the fact that alleles at a single locus can produce a ‘continuous’ trait in the manner described.
b. phosphatase test, a test applied to dairy products to find whether they have been adequately pasteurized.
1933Kay & Graham in Jrnl. Dairy Res. V. 70 If..the cream was pasteurised, its phosphatase content was completely or almost completely destroyed. This suggested to us the possibility that the phosphatase test might also be used for determining whether a given sample of butter had been made from fresh or from pasteurised cream. 1960Judkins & Keener Milk Production & Processing xiv. 256 The phosphatase test is very sensitive and will show very small variations in the time and temperature of pasteurization. As little as 0·1 per cent raw milk in pasteurized milk is also easily detected by this test. 1975J. W. G. Porter Milk & Dairy Foods xi. 55 The phosphatase test shows whether the proper temperature has been reached during pasteurization. |