What result allowed Dintzis to conclude that proteins are synthesized from the N terminus to C terminus

The more newly synthesized peptides had greater levels of radiolabeled H

Explanation:

Using immature red blood cells (reticulocytes), Dintzis showed that polypeptide chains of hemoglobin were created from N-terminal to the C terminus during translation. Dintzis labeled with radioactive amino acids that were being actively translated, subsequently digested the translated proteins with trypsin and finally determined the amount of tryptic protein fragments. From this experiment, Dintzis observed that the radioactive products were concentrated in the C-terminus (i.e., labeled amino acids appeared first in the C terminal tryptic peptides), thereby showing that the direction of protein synthesis is from the N terminus to the C terminus.