Welcome everyone. My name is Dr. Douglas Houston.
I'm a senior lecturer at the University of Edinburgh.
Today I'm going to be talking about "The Biochemistry of DNA and RNA".
The lecture is split into two parts.
The first part will be zooming right in on the chemistry of these molecules,
and then for the second part,
we will be looking at the relevance of this chemistry
to the biological function of these molecules.
So Part 1.
Just to introduce to you a little bit of history behind the structure of DNA.
The structure of DNA was first elucidated or discovered in 1953, or at least,
that's when the famous paper was published by Watson and Crick,
two scientists who you might have heard of,
but also with a lot of input from another scientist called Rosalind Franklin.
They used a technique called X-ray diffraction to
essentially measure the repeating pattern in the structure of DNA.
So it's similar to a technique called X-ray crystallography,
which you may have heard about.
But this was a rather more old-fashioned technique that didn't require crystals.
It's actually fiber diffraction.
They actually were able to deduce from
the diffraction spots on a photographic film caused by the diffraction of X-ray waves,
this repeating pattern, and from that,
they were able to build a molecular model of
how the various chemical components of the polymer fit together.
This first half of the lecture,
we'll be talking a lot about the specifics of how
these different parts of the molecule interact.