dna hakkında aradığından fazlası

majör rna

8/1/2008 · Kategori: dna

Major RNAs

There are three major classes of RNA in the cell:

mRNA

messenger RNA carries the genetic information that will be expressed ultimately as proteins. In prokaryotes, it is short-lived and is turned over rapidly. Eukaryotic mRNA is more stable as a result of the modifications that are made to it after it is transcribed.

 

tRNA

transfer RNA is the adapter molecule. It recognizes the codons of the mRNA on the one hand, and it can be covalently bonded to the appropriate amino acid, on the other.

 

rRNA

ribosomal RNA is found in the ribosomes.

Prokaryotic ribosomes have 3 rRNA molecules: 23S, 16S and 5S.

Eukaryotic ribosomes have 4 rRNA molecules: 28S, 18S, 5.8S and 5S.

rRNA was once thought to be an inert scaffold for the ribosomal proteins. We now know that the 23S (and 28S) rRNA is the catalytic agent in protein synthesis.

 

Non-coding RNAs (ncRNA)

It has recently become clear that botyh prokaryotic and eukaryotic cells contain a large number of small RNA molecules with a diversity of ********s in processes such as regulation of tran******ion, repliation of eukaryotic chromsomomes, RNA processing, RNA modification, RNA editing, mRNA stability and degradatrion, regulation of translation, and protein translocation.

The following table from a review article in Science lists processes affected by ncRNAs and gives some examples.

Kalıcı Bağlantı Yorum (0) Yorum yaz! Arkadaşına Gönder!

0 yorum yazılmıştır