The Relation of Optical Form to the Utilization of Amino Acids. II. Utilization of Stereoisomeric Varieties of Aspartic Acid and Asparagine by Carrot Root Disks.

Publisher Website
Google Scholar
Abstract
The uptake and utilization of the stereoisomers of aspartic acid and asparagine as well as the effect of the former on the uptake and utilization of ammonium-N by carrot root disks were investigated. The results show that L-aspartate was absorbed much faster than its anti-pode. The amount of D-aspartate absorbed during 24 hours was less than 50% of that of L-aspartate, when they were externally supplied, alone or in combination with ammonium sulphate. L-aspartate was markedly utilized causing a greater increase in the protein than in amides when supplied alone, but more amides than protein when supplied in combination with ammonium sulphate. L-aspartic acid was rapidly assimilated forming liberally glutamine; asparagine was formed, however, at a lower rate. On the other hand, D-aspartate taken up by carrot root disks behaved as inert metabolite. L-aspartate enhanced the absorption and utilization of ammonium-N, but D-aspartate depressed both processes. Asparagine was taken up as intact molecules, and almost all asparagine absorbed accumulated as such in the cells.