Of the three molecules participating in
the central dogma: DNA, RNA and proteins;
RNA probably has the most diverse
set of functions of any of them.
In this talk I will give some background
about the different types of RNA,
discuss the structures and
functions of the various RNAs,
and then give an example of gene
expression in a prokaryotic system.
Now RNA, of course, is made from
DNA in the process of transcription
and the copy of DNA is made
into RNA using the nucleotides
U, G, C and A.
RNA is processed by various
enzymes known as RNAses.
And RNA can also be completely
broken down by various other RNAses.
So it's a relatively unstable molecule to work with.
Some viruses like HIV or
measles and flu virus
actually use RNA as their genetic material and not DNA.
So the role of RNA in the central dogma
is central to the central dogma.
Now the central dogma, of course,
says that DNA copies itself,
DNA makes RNA and RNA can
in some cases go back
to DNA by reverse transcriptase, as we have seen.
But more importantly RNA goes and makes protein and that
protein is essential, as we have seen, for all living cells.