Video Transcript
Peptidyl transferase catalyzes the
blank bond formation to link two amino acids in a growing polypeptide chain. (A) Hydrogen, (B) ester, (C)
glycosidic, (D) peptide.
In order for a gene in DNA to be
converted into a protein, it needs to go through two steps. The first step is called
transcription and involves converting DNA into mRNA. The second step is called
translation, where the sequence of mRNA is converted into a sequence of amino acids
to form a polypeptide. This polypeptide can then go on to
fold into a protein with a specific shape and function. Let’s talk about some of the
details of translation to answer this question.
Translation is performed by an
organelle called the ribosome. It is made up of two subunits, the
large and small subunit that sandwich together the mRNA molecule. The sequence in mRNA is matched to
incoming tRNA molecules that bring the corresponding amino acid. These amino acids are linked to the
growing polypeptide chain that is coded for by the mRNA sequence. The ribosome links these incoming
amino acids using its peptidyl transferase enzymatic activity. This new bond that peptidyl
transferase forms is called a peptide bond.
Therefore, in the statement
“Peptidyl transferase catalyzes the blank bond formation to link two amino acids in
a growing polypeptide chain,” the answer choice that correctly fills in the blank is
given by answer choice (D), peptide.
