Question

how is a eukaryotic transcript different from finished mRNA? what about a prokaryotic primary transcript?

Answer 1

How is a eukaryotic transcript different from finished mRNA?

A eukaryotic primary transcript goes through 3 steps as it leaves the nucleus.

i. A cap is placed on the 5' end,

ii. Poly A tail is added to the 3' end and

iii. Introns are spliced out of the interior of the primary transcript.

What about a prokaryotic primary transcript?

On the other hand, in a prokaryotic primary transcript, no processing is present as there is no separation of nucleus and cytoplasm in prokaryotes. Ribosomes are attached to the transcript and start translation even before the transcription is finished

Additional information:

Difference between Transcription and Translation in prokaryotes and Eukaryotes:

Prokaryotes	Eukaryotes
1. Both transcription and translation occur in the cytoplasm as there is no distinction in prokaryotes	1. Transcription takes place in the nucleus while translation occurs in cytoplasm in ribosomes
2. The RNA from transcription can be translated immediately by ribosomes and tRNA	2. Translation occurs in cytoplasm. RNA made by transcription (pre mRNA) is processed to become mature mRNA
3. Translation can begin before transcription is finished	3. Translation cannot begin before transcription
4. The primary transcript is mRNA	4. The primary transcript is processed mature mRNA
5. No RNA processing is involved	5. After processing, mRNA is exported from nucleus into cytoplasm