Question

On the ribosome, the mRNA is read from ..., and the polypeptide chain is synthesized from...

a) 5' to 3'; C- to N-terminus.
b) 5' to 3'; N- to C-terminus.
c) 3' to 5'; C- to N-terminus.
d) 3' to 5'; N- to C-terminus.
e) random, N- to C-terminus

Answer 1

In the ribosome, mRNA is read from the 5' to 3' direction, and the polypeptide chain is synthesized from the N-terminus to the C-terminus. tRNA molecules match their anticodons with codons on the mRNA to add amino acids to the growing polypeptide in the correct order.

Step-by-step explanation:

The messenger RNA (mRNA) is read by ribosomes in the course of protein synthesis. During this process, the ribosome moves along the mRNA strand in the 5' to 3' direction, as indicated in previous figures and descriptions. Starting with the initiation phase, a ribosome binds to the mRNA and translation begins. This is followed by the elongation stage, where tRNA molecules bring amino acids to the ribosome, matching their anticodons with the codons on the mRNA strand. The tRNA presents its amino acid to be added to the growing polypeptide chain, which is synthesized from the N-terminus to the C-terminus. The elongation process continues until a stop codon on the mRNA is reached, signaling the termination of translation and release of the completed protein.