Question

Explain why each of these is important in transcription in prokaryotes and eukaryotes

5' cap

shine deigarno sequence

f-met tRNA

A site

Peptidyl transferase

Answer 1

Answer-

According to the given question-

Transcription - DNA -----> RNA is called transcription where the information present in DNA are transferred into mRNA with the help of enzyme DNA dependent RNA Polymerase.

Translation - mRNA -----> Protein , Where the information present in the form of triplet codon is translated into Amino acid chain.

In prokaryotes Transcription and translation occur in side the cytosol, while in eukaryotes Transcription occur in nucleus producing Pre -mRNA which is through processing  converted into mature mRNA by adding 5, cap and 3, Poly A tail as well as removal of non coding region called intron from Pre mRNA and joining of coding region called exon . after that mature mRNA is comes out of the nucleus onto cytoplasm where translation takes place on ribosome.

Organism	Prokaryotes	Eukaryotes
5' cap	No RNA processing occur in prokaryotes , because transcription and translation both occur in cytoplasm and transcription and translation occur simultaneously in prokaryotes.	5 ′ cap which is 7-methylguanosine ,is added during RNA Processing in eukaryotes which helps in protection of newly formed mRNA from degradation and this cap also helps in binding of pres-initiation complex during translation.
Shine-Dalgarno sequence	It is the binding site for ribosome in prokaryotes messenger RNA, Which are present approximately 8 base upstream of AUG or start codon .	Shine-Dalgarno sequence is not found in eukaryotes, but in  eukaryotes there is Kozak consensus sequence which is a nucleic acid motif which work as  translation initiation site.
f-met tRNA	also called N-formyl-methionyl-tRNA which is aminoacyl-tRNA responsible for initiating  protein synthesis in prokaryotes. Code for this is AUG, but can also code for  GUG and CUG.	Not found in eukaryotes. There is methionine amino acid which are coded by AUG work as initiation codon.
A site	also called acceptor site and work as  binding sites for tRNA which carry new amino acid to A site.	also called acceptor site and work as  binding sites for tRNA which carry new amino acid to A site.
Peptidyl transferase	Found in large subunit​​​​​​​ of 50 S or 23S component of ribosomes and act as ribozyme, responsible for formation of peptide bond between two amino acid.	Found in large subunit​​​​​​​ of 60 S or 28 S component of ribosomes and act as ribozyme, responsible for formation of peptide bond between two amino acid. ​​​​​​​