Influence of Certain Amino Acids Upon the Enzymic Hydrolysis of Starch

Influence of Certain Amino Acids Upon the Enzymic Hydrolysis of Starch : Dissertation Submitted in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy in the Faculty of Pure Science, Columbia University (Classic Reprint)

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Excerpt from Influence of Certain Amino Acids Upon the Enzymic Hydrolysis of Starch: Dissertation Submitted in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy in the Faculty of Pure Science, Columbia University Each of the four amino acids here studied as well as aspartic acid and asparagine previously investigated, showed a similar favorable influence upon the enzymic hydrolysis of starch. The addition of a mixture of two amino acids produced no greater effect than would result from the same concentration of one of them. In these experiments the favorable effect of the added amino acid was not due to any influence upon hydrogen ion concentration nor to combination of the amino acid with the products of the enzyme reaction. The addition of one of these amino acids is a very effective means of protecting the enzyme from the deleterious influence of cupric sulphate and may even serve to restore to full activity an enzyme which has been partially inactivated by copper. The favorable influence of the amino acid is evidently due in part at least to a protection of the enzyme from deterioration in the aqueous solution in which it acts. This view is supported by the following facts: (1) Solutions of pancreatic amylase (containing optimum concentrations of chloride and phosphate) which have stood 1 hour at 4dc. Show greater activity when alanine has been added to the solution in advance. Amylase solutions to which the chloride and phosphate have not been added are protected by alanine at 22c. (2) There is a striking increase in activation by glycine and phenyl alanine with increased temperature until coagulation oi the enzyme occurs. (3) At the same temperature, there is greater apparent activation when hydrolysis is allowed to proceed for 1 hour than when the action is stopped at the end of 30 minutes. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.show more

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  • Paperback | 26 pages
  • 152 x 229 x 1mm | 50g
  • Forgotten Books
  • United States
  • English
  • , black & white illustrations
  • 024308515X
  • 9780243085156