Wednesday, 12 May 2010

Some RNAs are bigger than others

Using this blog for revision hasn't been my way of doing things, because I don't want to put loads of stuff on here that's kind of unaccesible, but the majority of what I need to know is a bit unaccesible, therefore hard to write about too. I'm just reading stuff and not taking much notes at all.
Anyway I made this picture a day or two ago to illustrate the roles of RNA. Everyone's heard of DNA, but really, it's the very similar but much more dynamic RNA that actually get some stuff done. OK last time I said that proteins were where the action is, and that's true, mostly. But you're not gonna get any proteins without RNA first. RNA is both the messenger and the constructor of proteins.
In fact, RNA was quite likely the first molecule of life, since it can catalyse reactions on it's own. Protein formation would've been the next step, creating more efficient enzymes, before evolution then settled on DNA as the most stable carrier of information. Which puts a different perspective on things I think. I won't get into the wonder that is the origin of life for a good while yet though, it' just really mind boggling.
Anyways, I'm sure no-one's really reading but here's the picture. All those RNAs have different role's and are different shapes and sizes. We're still learning a lot about what they all do and how they might be used. For example, RNA interference (RNAi; the effect of short, double stranded RNA effecting genes after transcription) was only discovered in the early 90's and was a complete surprise.
Fun fact: small nuclear RNAs form complexes with proteins to form snRNPs. My textbook tells me these are pronounced 'snurps'.

These are the essential processes in turning biological information into action, and that's why  they've been called the Central Dogma. Although I don't like the word dogma used in science, it's clear that this stuff needed an important sounding name.

All that metabolism shit will be covered soon. That's what my second exam is about. Joy.

Saturday, 8 May 2010

Number 3

A few months ago when I started this blog I wanted to write a bit about why certain things interest me, to establish the purpose of this place. It seems a good time, what with all this parliamentary palaver to post something I wrote last year about politics, that I wanted to get in the Uni magazine. They didn't respond, and then this year I went off the idea of publishing in it when it went out of print. It's wholly online now. I never thought it was very good anyway, to be honest. There were loads of typos. If I come up with something good I probably should try get it on there though, it'll look good on a CV. Oh god, that's a dreadful reason for doing things...

A little bit about little things that do stuff

What is protein? Well, most people think of meat, and maybe milk and cheese, or baked beans. Foods that are rich in protein, that we need to live. In fact the vast majority of people in the western world over consume protein, but we can talk about that another day. Anyways, really we should say, what are proteins? 
The whole of biology is concerned in some way or another with what proteins do. If a living thing is like a car, proteins are the engine, and the hydraulics, and the wheels and the headlights. They are the doers in the situation, the moving parts. I guess the DNA would be the driver, and everything else would be the frame... 
OK so it's hard to make analogies with something as complex as a living thing, but basically proteins are a remarkably diverse collection of molecular machines. And yet the elegant thing is that they are really fairly simple. They're composed of 22 possible basic ingredients (Amino acids), which are put together in chains, which then fold up around themselves. These are then sometimes garnished with a few extra bits, called aesthetic groups. And then they can all play together and with pretty much any other kind of molecule and make stuff happen. Let the whole thing go for a few billion years and abra-cadabra, you have life as we know it. 
OK evolution is a bit more complicated, and yeah DNA is what carries the instructions, but really, the double helix can bugger off out of the limelight. The science guys on TV seem to be very impressed about the whole code-of-life story, but I think that misses the point a bit; it's proteins that are the actual prose of life, DNA is more like the alphabet. I think it's more exciting that we're now figuring out what the words actually mean, rather than the fact that we managed to get what the letters sounded like. How's that for analogy? At least now I'm slightly more excited about the funny things life is made of.
So my first exam is just all about these tiny little buggers, how they do business with their co-conspiritors the nucleic acids (DNA and RNA) and how we study them. It's really important, fundamental stuff, and there's alot of it. So I need to get down to the details today, hardcore. But it's doable... it's the other exams I 'm more worried about.

This odd shape is the structure of my favourite protein of the moment, luciferase. It's what makes the light in a firefly. It's name is just a name for the devil plus -ase, which means a protein that makes a reaction happen. In this case, a pretty cool reaction, which I can talk about more when I go into pyrosequencing; using flashes of light to read a strip of DNA... 
Yeah, this revision thing'll get done, no problem...

Here is the best acronym I have ever found, which I came across during my brief time I actually did, sorta, revise. If you want to know what that unexpected protein was in that sample, you can just check if it's cRAP. Science is for people who like cool names.

P.S. This post counts as yesterday, because I haven't been to bed yet. So I'm not due a facial poke. This counts as revision, doesn't it? No?

Friday, 7 May 2010

Fruit flies like a banana.

Time flies like an arrow; fruit flies like a banana.

This is a fruit fly. They're nice little things, and very important too. They're model organisms, scientists' bestest friends.

Anyway, about the time flying... I must have put in a bent shot somewhere, because my arrow's really off target. That counter keeps counting, but I don't seem to be learning what I need to be learning. 

If I were really interested, clearly, I would be soaking it up, like I''ve soaked up other miscellaneous interesting things I've read. But wierdly my interest is hard to muster when it must be mustered. I am more interested in mustard, right now, than my six exams. I guess because it scares me, revision, if I'm honest.

So all the next posts from now are me convincing myself about some topics being interesting. Hopefully learning about them at the same time.

If you're not me, this will give you an idea of what I've 'studied' this year.

All the things I need to learn are related to human health, but it seems to me not organised as a comprehensive look at that enormous topic. It's more like a hodge-podge look at a bit of chemistry and a few diseases. But that is how it has to be I guess, and when you're missing 40% of lectures it'll probably always seem a hodge podge.

 P.S. No-one called to berate me after last week's non posting of revision notes. I mean, my girlfriend tries, but berating goes against her kind nature

P.P.S. If there is not a revision posting everyday for the next two weeks from now, you can poke me in the cheek. Hard.