- a. mRNA binds to the small ribosome and the first tRNA binds to the start
- (AUG) codon on the mRNA
b. the large subunit now attaches to the small subunit
- c. the polypeptide chain elongates. The
- second tRNA molecule binds to an mRNA codon at the A site.
This tRNA brings another amino acid . The ribosome moves down the mRNA chain, allowing the tRNA to read each codon in the mRNA. The tRNA brings an amino acid for each codon it reads.