Question: what does maths and computer code have to do with protien

Jonny Brooks-Bartlett answered on 13 Jun 2015:

This is a fantastic question and in fact I was asking myself the same question about 2 years ago.

So let me set the scene with some information on my profile page:
“When things get really small, like the cells that make up our body, we use a microscope to see them. But some of the things that we want to see (like proteins) are just too small to see under a normal microscope. Instead we have to shoot crystals that are made of these really small things with X-rays instead of normal light. Doing this creates certain patterns that we call diffraction patterns. We can analyse these patterns (with MATHS) to work out what the small object looked like.”

These diffraction patterns are basically lots of spots on an image (see the last picture on my profile page for an example: /lutetiumj15-zone/profile/jonnybrooksbartlett/)
We usually get hundreds of these images and so the number of spots that we get are usually in the thousands.

Why do we care about the spots and where does the maths come in?

It turns out that the intensity (brightness) of these spots is dependent on the number of electrons in the crystal and using more information about the X-rays called the phase we can use a mathematical equation to put all of the information together to work out what the protein looks like. The equation is called a Fourier transform and it’s quite complicated. But if you can use it then you can work out the structure from the spots! This is why we need maths.

Ok so where does the computer code come in?

Well as we said, we get thousands of spots and so each spot needs to go into the equation. Writing thousands of numbers on a piece (or pieces) of paper may get very boring (I haven’t tried it but I can imagine it wouldn’t be very fun) and you could make many mistakes.
Instead we write computer code to do the calculations for us. They are much better at doing these types of calculations than humans anyway.

To be honest, behind the majority of areas of science there is maths and computer code. My housemate who is a molecular biologist said to me that his best skilled that he’s learned doing science is writing computer programs because they are so useful and make things much quicker.

I hope this answers your question 🙂