. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. ATP-ASE OF MVTILUS SPERM. II 329 removed by centrifugation and the entire supernate analyzed for orthophosphate by the microcolorimetric method of Taussky and Shorr (1953). Optical density was measured in a Coleman, Junior spectrophotometer at a wave-length of 660 millimicrons. Protein content of the sperm tail samples was estimated by a modification of the method described by Nielsen (1958). RESULTS Temperature-dependence of flagellar ATP-asc. Duplicate determinations of the enzyme activity at various temperatures over a ra
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. ATP-ASE OF MVTILUS SPERM. II 329 removed by centrifugation and the entire supernate analyzed for orthophosphate by the microcolorimetric method of Taussky and Shorr (1953). Optical density was measured in a Coleman, Junior spectrophotometer at a wave-length of 660 millimicrons. Protein content of the sperm tail samples was estimated by a modification of the method described by Nielsen (1958). RESULTS Temperature-dependence of flagellar ATP-asc. Duplicate determinations of the enzyme activity at various temperatures over a range from 1° to ° C. show a fairly constant increase in rate up to about 20° C., virtually a doubling for each . . . . . . = X103 FIGURE 2. Temperature dependence of Mytilus sperm tail ATP-ase. Arrhenius plot of data in Figure 1. Ordinate, logarithm of rate of phosphate liberated; abscissa, reciprocal of temperature, I/degrees, Absolute. ten-degree rise (Q10 -- 2) (Figure 1). Between 20° and 30°, the rate of dephos- phorylation levels off and then declines fairly uniformly. From the slope of the Arrhenius plot (Fig. 2), the activation energy of the reaction was calculated to be - 10,450 Since these determinations have been made on crude preparations, on "whole" tail suspensions, rather than purified enzyme extracts, this finding suggests that the broad temperature range of maximum enzyme action may simulate the situation which occurs during natural spawning. This coincidence may be of significance in that when associated with other factors (chemotactic, antigenic, etc.; cf. review by Rothschild, 1956) which may operate to assure maxi- mum fertilization, optimum swimming activity of the spermatozoa may further serve. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrati
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
