[Omar1994]

if only there were answers to those questions ^ here

[lagoom]

(Original post by sag_2u07)
http://www.youtube.com/watch?v=O5eMW4b29rg
I found this video and at like 5:00 min it shows how the GALP is made into another product biphosphate sth and THEN it can make two ADP into ATP...but we don't have to learn it but yeah...hope it answers your question

hey thanks! i'll have a look at it later cba at the moment lol

[-James-]

Can someone please explain the role of ATP in muscle contraction? Does the hydrolysis of ATP cause it to change shape and move but when ATP reattaches, it detaches so it can bind again to the next part og actin?

[ELB141]

Does anyone have a good guess what may come up in unit 5? Our mock was January exam and it was pretty much all on anaerobic respiration so I'm guessing that won't come up a lot again!


This was posted from The Student Room's iPhone/iPad App

[-James-]

Could someone outline the stuff they know about glycolysis?

I think im lacking stuff cause all I know is that the glucose is unreactive do phosphate attaches to the glucose which breaks up into 2 carbon compound and And 2 ATP is needed. Then, this intermediate 3 carbon compound is reduced to pyruvate and this creates 4ATP due to substrate level phosphorylation and 2H are taken up by the NAD coenzyme

[sunshinesmile10]

how are you all revising...im really stuck for questions to do. Please some tips...where can i find some papers ad all

[sag_2u07]

(Original post by -James-)
Could someone outline the stuff they know about glycolysis?

I think im lacking stuff cause all I know is that the glucose is unreactive do phosphate attaches to the glucose which breaks up into 2 carbon compound and And 2 ATP is needed. Then, this intermediate 3 carbon compound is reduced to pyruvate and this creates 4ATP due to substrate level phosphorylation and 2H are taken up by the NAD coenzyme

You need to know the intermediate that converts into pyruvate is TP and glycolysis occurs in cell cytoplasm.
That's really glycolysis in a nutshell and all you need to know. And then you just have to know that after glycolysis if oxygen is present, then links and rest of the aerobic pathway takes place. If oxygen isn't present then anaerobic pathway which involves converting pyruvate into lactate or ethanol. Anaerobic allows regeneration of NAD to go back into glycolysis so small amounts of ATP can be released at each cycle in an emergency. Oh and you need to know the fate of lactate.

[EmanFirstLast]

(Original post by 19941994)
No we're not allowed :/


This was posted from The Student Room's iPhone/iPad App

How do you know this ? I have seen people on this website say they are allowed to bring there own copy with notes written on it.. ?

[19941994]

(Original post by EmanFirstLast)
How do you know this ? I have seen people on this website say they are allowed to bring there own copy with notes written on it.. ?

We're definitely not allowed to, my teacher said that we will be given new ones in the exam :/ also, if we were allowed notes then thats just basically bringing answers into the exam, which i highly doubt they would allow

[hankypanky3]

Hi there guys.. can you please help me with the kymogramph trace..I dont seem to get how they calibrate it

http://fronter.com/greenwich/links/files.phtml/953912613$238383000$/Student+Resources/A2+Biology+snab+Activites/AllA2_activity_sheets.pdf

Activity sheet 7.13

[Backflip]

(Original post by hankypanky3)
Hi there guys.. can you please help me with the kymogramph trace..I dont seem to get how they calibrate it

http://fronter.com/greenwich/links/files.phtml/953912613$238383000$/Student+Resources/A2+Biology+snab+Activites/AllA2_activity_sheets.pdf

Activity sheet 7.13

I cant access your link, but if you mean using a kymograph to record a spirometer tracing - It can be calibrated by forcing a known amount of air (eg 1dm^3)into the spirometer chamber, the spirometer chamber moves up and so the pen moves up too. The change produced in the trace on the paper can then be measured.

So for example; if 1dm^3 causes a 10cm change then each cm on the paper is 0.1dm^3.

Does that make sense?

[This Honest]

QP: http://www.edexcel.com/migrationdocu...e_20110127.pdf

Q5ci- I don't understand the question or the mark scheme. Can someone please explain it to me.
It's jan 11

MS: http://www.edexcel.com/migrationdocu...s_20110309.pdf

[Cleoleo]

do we need to know about Alzheimer's in deatail like depression, MDMA and parkinson's diseasE?

[Cleoleo]

'Describe how breathing rate and tidal volume can be determined from a
spirometer trace.'


What does the mark scheme mean by 'reference to time (for one / several peaks)'?

[ghogho]

i left three questions empty the exam was really weired and tough!!!!!!

well pple lets forget about uint 4 its done all what we can do is to send a complaint to edexcel on their website....

and nw lets concentrate on unit 5 and be optimistic hopefully it will be much much better than unit 4

note...
whoever read this post plz smile , keep optimistic , work hard and finally pray that unit 5's exam will be much much better than unit 4 and we all finish before time is up...

best of luck for all of us ;D

[This Honest]

(Original post by ghogho)
i left three questions empty the exam was really weired and tough!!!!!!

well pple lets forget about uint 4 its done all what we can do is to send a complaint to edexcel on their website....

and nw lets concentrate on unit 5 and be optimistic hopefully it will be much much better than unit 4

note...
whoever read this post plz smile , keep optimistic , work hard and finally pray that unit 5's exam will be much much better than unit 4 and we all finish before time is up...

best of luck for all of us ;D

Could you please help me on post #117

[Cleoleo]

(Original post by This Honest)
QP: http://www.edexcel.com/migrationdocu...e_20110127.pdf

Q5ci- I don't understand the question or the mark scheme. Can someone please explain it to me.
It's jan 11

MS: http://www.edexcel.com/migrationdocu...s_20110309.pdf

would like to know why the mark scheme says this ans too..... anyonee?
when I did the q, i thought it wanted us to talk about lactate being oxdised to pyruvate but then it does say 'aerobic respiration' gaah.

[This Honest]

(Original post by Cleoleo)
would like to know why the mark scheme says this ans too..... anyonee?
when I did the q, i thought it wanted us to talk about lactate being oxdised to pyruvate but then it does say 'aerobic respiration' gaah.

Sometimes the MS just says stuff which confuses me.
Also, in some questions, there are some points which I thought was totally irrelevant yet it was in the MS

[Cleoleo]

(Original post by This Honest)
Sometimes the MS just says stuff which confuses me.
Also, in some questions, there are some points which I thought was totally irrelevant yet it was in the MS

ikr! sigh.

edit:

do you thibnk you can help me out on this please?

'Describe how breathing rate and tidal volume can be determined from a
spirometer trace.'


What does the mark scheme mean by 'reference to time (for one / several peaks)'?

[This Honest]

(Original post by Cleoleo)
ikr! sigh.

edit:

do you thibnk you can help me out on this please?

'Describe how breathing rate and tidal volume can be determined from a
spirometer trace.'



What does the mark scheme mean by 'reference to time (for one / several peaks)'?

I didn't answer this because I wasn't too sure
However, I think breathing rate can be determined by the number of peaks in the spirometer trace. So a trough and a peak is 1 breath.
Tidal volume is the difference in volume of gas breathed in between each peak

Haven't revised that fully but that's what I can think off

Not sure why MS says that....biology mark schemes are so vague