Questions & Answers

Peptidyl transferase plays an important role during protein synthesis. What is true about this enzyme?
(a) It is proteinaceous
(b) It is RNA as a catalyst
(c) It helps in peptide bond formation
(d) Both B and C

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Hint: The substrates that are used for the peptidyl transferase response are the two tRNA atoms, the first one is one bearing the developing peptide chain and subsequently the second one is bearing the amino alkanoic acid which will be added to the chain.

Complete answer:
Due to the essential enzymatic capacity of the ribosome, the peptidyl transferase is an amino acyltransferase additionally, which structures peptide connections between contiguous amino acids utilizing tRNAs during the translation cycle of protein biosynthesis. It is one among the enzymes that are non-proteinaceous in nature rather it acts as a ribozyme, which suggests here RNA acts as a catalyst.

Additional information: The ribosomal peptidyl transferase center (PTC) resides in the large ribosomal subunit (the 50S), were two fundamental biological reactions are processed and catalyzed: peptidyl transfer, the formation of a peptide bond during protein synthesis, and peptidyl hydrolysis, the discharge of the entire protein from the peptidyl tRNA upon completion of translation. Prokaryotic ribosomes contain two subunits, the monstrous 50S subunit, and accordingly the more modest 30S subunit; together they structure the 70S ribosome, a subatomic machine that chooses its substrates, aminoacyl-tRNAs (aa-tRNAs), quickly and precisely and catalyzes the blend of peptides from amino acids. The 30S subunit contains the decoding site, where base-pairing interactions between the mRNA codon and therefore the tRNA anticodon determine the choice of the cognate aa-tRNA.
So the correct answer to the above question is ‘(d) Both B and C’.

Note: Peptidyl transferase speeds up the reaction by lowering its energy of activation. It does this by giving legitimate direction to the response to happen. The peptidyl transferase provides proximity, meaning that it brings things closer together, but it does not provide an alternate mechanism. Instead, it provides proper substrate orientation, increasing the probability that the prevailing mechanism will occur.