Belated congratulations to everyone who got what they wanted from the results last week. I haven’t been into school yet so I don’t know how individuals did, other than an odd few bits that Mr Murray forwarded me.
I thought I’d suggest a few guidelines for writing out longer answers (or what we might call scientific essays). It’s not something we spend a lot of time in schools overtly teaching, and you will come across different opinions and styles for this, but I’m going to stick to ways to improve your writing for scientific purposes. Since a part of the homework for the holiday was an essay about oxidative phosphorylation, you may well get some clues here as well.
Rather than give too much away, I’ll use Krebs cycle as an example. Imagine you had a 9 mark question about Krebs Cycle on a question paper. My suggestion would be to start by getting down as many things you could think of to do with krebs, forget structure for a moment and brain-storm for a minute.
Let’s say you wrote down citrate, 654444, ATP, NAD, FAD, pyruvate, maybe you also draw a rough version of the cycle. Once you have some ideas down, you can build a structure from there. For example, drawing out the cycle might have made you think of the link reaction, perhaps you then remembered about the CO2 being removed which leads you to decarboxlase, maybe some other enzymes. Many of the structured (or long answer) questions you will come across in biology are based around step by step processes, which gives you a ready-made structure. The problem people often have is they start too quickly, forget a part of the process and then find it difficult to think backwards to what has been missed out. A good tip is to give a description for every scientific term used (within reason!), e.g. ‘…two hydrogen are removed from the citrate by NAD. NAD is a coenzyme that is reduced in this reaction, and used to carry electrons’ . You described the role of NAD which is relevant to the question, but not the coenzyme part, which would be more detail than is necessary.
When it comes to writing an essay, the process is similar but you have longer to plan things out. The first paragraph of your essay should always give the overview. A good example of this is to look at this description of the Cori cycle (don’t worry about what it is yet) from wikipedia. The information about who it is named after is not very relevant, but notice how it encapsulates what the article is about. The bulk of the article then goes on to talk about the details; notice how you are expected to understand what most words (oxygen, glucose, pyruvate) mean. Because of the nature of wiki articles, important words are linked, remember you will not have that luxury so make sure that you describe anything that is important.