Clxvii. Studies on Plant Amylases. I. the Effect of Starch Concentration upon the Velocity of Hydrolysis by the Amylase of Germinated Barley

IT is clear that, for the determination of enzymic reaction-velocity under readily definable conditions, the states near the initiation of the reaction are decidedly the best. Usually however this part of the progress has been left unexplored and delineation of it has been based merely upon empirical expressions of doubtful value. In the present paper data have been directly collected within a few minutes of the origination of the reaction on the mixing of enzyme and substrate. From these data "initial slopes"' are determined graphically and used as a measure of reaction-velocity. In experiments of this short duration the difference between apparent and true zero-time becomes significant.