what is the role of introns and exons in RNA?

Answer 1

It was generally assumed that the sequence in any given intron is "junk DNA" with no function. More recently, this is being questioned however; it is known that introns contain several short sequences that are important for efficient splicing. The exact mechanism for these intronic splicing enhancers is not well understood, but it is thought that they serve as binding sites on the transcript for proteins that stabilize the spliceosome. It is also possible that RNA secondary structure formed by intronic sequences may have an effect on splicing, and in alternative splicing, an exonic sequence in one product is intronic in another. "Old code" sequences, on the other hand, in mose cases indeed seem to be "evolutionary kibble".

In many genes, each exon contains part of the open reading frame (ORF) that codes for a specific portion of the complete protein. However, the term exon is often misused to refer only to coding sequences for the final protein. This is incorrect, since many noncoding exons are known in human genes

Answer 2

Introns are a common eukaryotic event. Several features of interrupted genes are:

The sequence order is the same as in the mRNA
The structure of an interrupted gene is identical in all tissues.
Introns of nuclear genes have termination codons in all three reading frames.
Exon - RNA sequences in the primary transcript that are found in the mRNA
Intron - RNA sequences between exons that are removed by splicing

Answer 3

Introns are the part of the DNA that codes for proteins. Exons are bits of junk in between. Both the Introns and the Exons are transcribed from the DNA into the RNA messenger molecule. The exons are then removed before the RNA is exported from the cell nucleus for translation.

Answer 4

There is lots of DNA which as far as we know does not code for protein. Some of this DNA is found on the DNA outside of genes, but some non-coding DNA is found within genes. That's what introns are and as Jon said they have be excised from the primary RNA transcript before it becomes mature mRNA ready for transport out of the nucleus and for translation. Exons are the coding regions of the genes whose copies remain in the RNA after post-transcriptional modification to excise the intron copies.

Answer 5

introns stay in the nucleus and exons are put together or "spliced" together during mRNA processing. This also aids in producing variations between proteins.

Answer 6

introns dont do anything
exons travel out and get transfered into animo acids