Cellular respiration

[geordieg]

Can someone please explain glycolosis, oxidative phosphrolysation and the Kerb's cycle to me? I'm studing a -level biology over 15 weeks and i'm finding it really hard to study in this short time, this part has really got me baffled!

[gill3891]

I have recently studied this for my foundation degree and I found the book by McArlde, Katch and Katch really helpful in learning this whole thing. It is a hard subject to get grips with, but once you understand a bit of it, you will be fine. The book is quite expensive to buy but your college library may have a copy, if not try your city library. It is a hard subject to explain to other people, especially over writing....maybe someone else will be able to help you, unfortunately, I can only give you the name of the book that helped me learn it!

Bit of advice also, as your studying a-level, this book may be a bit more in-depth than you already know... don't try and understand the stuff you haven't learnt yet, there was some stuff there that even I didn't need to know. Just pick our the relevant parts! Hope it goes ok! xx

[gill3891]

That was supposed to read McArdle, Katch and Katch!

Hope it helps xx

[helsbels666]

Oh gosh!!! A level biology seems like an age ago! It was difficult

[helsbels666]

to remember krebs then!!! My best advice would be a simple (ish) revision guide. I used 'letts' and i know heinemann do one and a few others. It got me through.....

[geordieg]

Thanks all, i think i'm just a bit confused as to what happens in what order and why, as in does it happen in that order or are the seperate things etc aaargh hope i don't sound too thick!!

[Dr Hungry]

Hi, it's 2 years since I did A level Bio so I can't really remember the details, sorry. Basically:

1)Glycolosis comes first. It produces several ATP molecules and a few reduced co-enzymes, I forget how many. This happens in both anaerobic and aerobic respiration.

2) The pyruvate (I think) molecules then enter the Krebs cycle. This cyclical process produces some more ATP and some more reduced co-enzymes. Some CO2 is also made at this stage.

3) All the reduced co-enzymes produced so far have high energy electrons associated with them. These all go down the Electron Transport Chain, which in a roundabout way produces loads more ATP, much more than the previous two stages. The electrons and some H+ ions are then combined with Oxygen (from breathing!) to make H2O at the end. This is the process of Oxidative Phosphorylation, which happens in the ETC. This stage takes place on the stalked particles of the inner mitochondrial membrane.

Stages 2+3 only occur in aerobic respiration cos oxygen is needed to combine with the electrons at the end to make water. In anaerobic, only glyocolosis happens and the reduced co-enzymes get oxidised again, making ethanol in the process. That's why anaerobic yeast are used in brewing etc.

Sorry I can't be more specific with the enzymes involved or the amounts of things produced, like I say, it's been a while! You should probs look those things up. Good luck with the exam anyway!

[geordieg]

WoW Dr Hungry - you explained that so well, you should be a teacher (or a Dr, Dr Hungry). 'By Jove, she's finally got it.' Thanks thanks and thanks again.

[Dr Hungry]

No worries. I'm just a Med student at the mo, so not even a proper doctor yet, but it's nice to know I have another career if this one goes pear shaped! Good luck with the biology!

[geordieg]

You'll make a fantastic doctor I'm sure! Where are you studying?

Thanks again xx

[Dr Hungry]

Why thankyou! I'm at UEA, in Norwich which is normally a great place to be, but I've got 7 exams coming up in the next few weeks, so it's all a bit frantic at the moment.

How come you only have 15 weeks to learn A Level biology? It seems a bit mean to have to do it in so short a time. I'm sure you'll do great though.

[geordieg]

I needed the a level to apply for uni in september, applied for midwifery but got refused (to many applicants) so not sure what to do now - wait til the clearings list comes out i guess.

Anyhow, really really, lots of luck with all of your exams - that proves my theory that you'll make a really good doctor- after all you've got all of those exams coming up and you still found time to help me. Kindness and intelligence what more could you want in a doctor!

[Dr Hungry]

Well actually knowing some medicine might be a good start! But it's really nice of you to say that: both nice and hardworking from the sounds of it - seems like you would make a great midwife. I hope you get a place from clearing, you obviously deserve it.

Best of luck!!