Question

Initiation of protein synthesis in prokaryotes and eukaryotes is basically similar but there are some significant differences. Briefly discuss four differences in the processes of initiation of protein synthesis between prokaryotes and eukaryotes

Answer 1

Ans) Protein synthesis is the process in which cells build proteins. The term is sometimes used to refer only to protein translation but more often it refers to a multistep process in which cells follow a very systematic procedure that first transcribes DNA into mRNA and then translates the mRNA into chains of amino acids.

Initiation of protein synthesis in prokaryotes and eukaryotes is basically similar but there are some significant differences.

The differences are

In eukaryotes,protein synthesis occurs in the cytoplasm but in In prokaryotes,protein synthesis begins even before the transcription of mRNA molecule is completed. This is called coupled transcription - translation.

Eukaryotic mRNA molecules are monocistronic, containing the coding sequence only for one polypeptide. in prokaryotes  In prokaryotes, mRNA molecules are polycistronic containing the coding sequence of several genes of a particular metabolic pathway.

In eukaryotes, most of the gene have introns or non coding sequences along with exons or coding sequences. The exons are joined together and introns are removed during mRNA processing. But Prokaryotes do not have introns (Except Archaebacteria).Therefore mRNA processing is not required.

The primary mRNA transcript in eukaryotes undergoes processing and splicing to change into a functional mRNA.But in  prokaryotes splicing of mRNA transcript does not occur.