Saturday, 7 July 2007

S204: TMA-4

Time to approach TMA-4. I must say the first time I looked at this it looked like gibberish! The essay question didn't look too bad, but the second question seemed impossible.


Write a report in which you discuss the statement ‘Extremophiles are only psychrophiles or thermophiles’ of 1200 words.

For this you have the books, but also a scientific paper was included attached to the question which summarised some of the different extremophiles. Extremophiles are organisms that live in extreme environments, psychrophiles being ones that live in cold environments, and thermophiles being those that live in hot, and when we say hot, we mean temperatures up to and above the boiling point of water.
Now I have to restrain myself, and not hand in an essay of
No. (1 word)

I've been interested in extremophiles for a while, so I knew there were a lot more types than the above. Writing 1200 words was difficult, as either you write a little about a lot of types, or a lot about a few of the types. Including diagrams was also not easy - there wasn't a lot to draw really.


A question about protein and gene analysis. The protein in question is spectrin, and the transcription factor GATA-1. I hadn't the first idea what to do with this question to start with. However - having conquered my fear a little, and had a longer look at the question, and also used the PDF search facility to locate spectrin in the text, I felt a little more confident.

The question starts off with getting you to define a few terms and come up with definitions for the protein and about transcription factors. There was also mention of luciferase which is a popular marker protein, as it comes from organisms like fireflies and so emits light.
Basically the start of the gene for spectrin had been glued onto the luciferase gene, and then tampered with in various ways, and you had to work out what it all meant. Along the way the GATA transcription factor is introduced and shown to affect the way the protein is produced, and you need to work out why, from graphical and tabular data.

I had to ask my tutor for clarification on one part, as it seemed to just be extracting numbers from a table, and describing a graph - both of which seemed rather simple.
I'd answered the whole question and was fairly happy with it mostly, when it occurred to me that the data we were given probably hadn't been just made up. After a bit of a pubmed search, I found the original paper they must have used for the question, including the same results. It wasn't actually that useful in helping to answer the question. It did make me feel slightly smug though!

As part of this work I also updated various of the wikipedia pages on various of the extremophile types, spectrin and GATA-1, which now includes this paper as a reference.

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