How to pronounce "xray"

And hemoglobin acts as a molecular sponge

to soak up the oxygen in your lungs

and then carry it to other parts of the body.

I was very much inspired by this image many years ago,

and I wondered whether we could use computer graphics

to represent the molecular world.

What would it look like?

And that's how I really began.

So let's begin.

This is DNA in its classic double helix form.

And it's from X-ray crystallography, so it's an accurate model of DNA.

If we unwind the double helix and unzip the two strands,

you see these things that look like teeth.

Those are the letters of genetic code,

the 25,000 genes you've got written in your DNA.

This is what they typically talk about -- the genetic code --

this is what they're talking about.

But I want to talk about a different aspect of DNA science,

and that is the physical nature of DNA.

It's these two strands that run in opposite directions

for reasons I can't go into right now.