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OCR Biology F212 Revision [3rd June 2013] (Now Closed)

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I'll give it try to explain...

PURPOSES:
Co-factors - they administer the binding between the production of enzyme-substrate complexes making it easier to form.
IMPORTANT: They act like your classical catalytic behaviour; they aren't consumed whatsoever within the reaction.
EXAMPLES: Magnesium ions are found in Hydrolase - the enzyme in charge of decomposing chemical bonds during Hydrolysis.

Co-enzymes - they are also described as organic co-factors.
- they participate in reactions whilst changing it.
- behaves as a carrier - there are more chemical groups between enzymes.

Helpful!?
This is not a huge aspect of the Enzymes module, but is a sneaky three/four mark in plain context, and around five maximum in a applicational context - with all their scene settings.

:biggrin:

Hope it helps!

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thankyou! that's really cleared that up for me!

regarding enzymes(not my strong point :colondollar:

), like where does activation energy come into it? i see it used in mark schemes here and there but what does it do

Reply 1281

mgmtunicorn

Original post by georgeturner1994

Someone breakdown Clonal expansion for me please

in b cell:
when the selected cell divides by mitosis to form plasma - then going onto become b memory cells which provide immunity or antibodies

in t cell:
after clonal selection occurs (where cell encounters complementary antigen, they divide (via mitosis) to become t memory which provides long term immunity, t helper cells which produce cytokines for b cells, and t killer that destroy infected body cell

hope this was as clear as it sounded in my head:c

Reply 1282

Ché.

Original post by mgmtunicorn

thankyou! that's really cleared that up for me!

regarding enzymes(not my strong point :colondollar:

), like where does activation energy come into it? i see it used in mark schemes here and there but what does it do

Oh, well!?
In terms of the effect it has on the activation energy, it will decrease meaning that more molecules or particles in a given volume or reaction will have the minimum or sufficient energy required to break reactant bonds - which is the function of your typical enzyme.

If you also study Chemistry - which I am not sure if you do - the Maxwell-Boltzmann Distribution is basically what that is implying!
(If you don't, I old like to apologise for mentioning it if you're stressing out!) LOL.

Activation energy is the part which might not be within the question title as such, but gets you marks for showing the background functioning within context to whatever they mention to us.

I am glad I could help!

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Reply 1283

username972634

Top tips for Biodiversity?

Reply 1284

Ché.

Original post by georgeturner1994

Someone breakdown Clonal expansion for me please

Sure!
CLONAL EXPANSION:
- After the activation of the T-helper cells during Clonal Selection - they B-lymphocytes then can divide by our good old friend, mitosis, which MUST be within the presence of the T-helper cells for plasma production and antibody production as a result.

IMPORTANT: I have described the Clonal Expansion of B-lymphocytes but it is important remember that Clonal Expansion happens first with T-lymphocytes activating themselves with the release of cytokines and all...
AND then it happens with B-lymphocytes in the process of forming plasma cells and memory cells in wider contexts.

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Reply 1285

Ché.

Original post by mastermdc

Top tips for Biodiversity?

Regarding what area, may I ask!?
:smile:

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Reply 1286

Kitnimohabbathai

jan 2010 grade boundaries anyone?

Reply 1287

Kitnimohabbathai

btw approximately how many marks are you guys losing in past papers?

Reply 1288

Kitnimohabbathai

also anyone have specimen mark scheme?

Reply 1289

Hardworker?

Bit of a big question..
Advantages and disadvantages of ex citu and insitu conservation for both animals and plants

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Reply 1290

Ché.

Original post by Kitnimohabbathai

jan 2010 grade boundaries anyone?

I cannot seem to find them!
But, then I checked on the bottom of their mark schemes - because that is where they use to supply them - and found it!

So...
A - 69;
B - 62;
C - 56...
:biggrin:

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Reply 1291

Ché.

Original post by Kitnimohabbathai

btw approximately how many marks are you guys losing in past papers?

Well!?
In my last couple examination mocks, I have lost around 9-10, almost every single time.

If you're aiming for full UMS, or even curious, the cap point is usually around 86/100 for 150/150UMS. :biggrin:

You!?

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Reply 1292

username1183214

Any predictions for long questions?

Reply 1293

Ché.

Original post by Hardworker?

Bit of a big question..
Advantages and disadvantages of ex citu and insitu conservation for both animals and plants

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I will give it a go...

IN SITU:
Advantages:
- Both the habitat and species are conserved effectively.
- Larger populations can be protected with minimal disruption.
- Species' recover quicker than Ex-situ conservation.

Disadvantages:
- Difficulty of controlling some factors that are actually threatening a species such as Poaching, Predators and Climate Change.

EX SITU:
Advantages:
- it can be used to protect a given species in a controlled environment from Predation and Hunting.
- Competition of sources are reduced.

Disadvantages:
- High expenses; small quantities can be catered for per process.

:biggrin:

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Reply 1294

Kitnimohabbathai

guys URGENTLY NEED the JAN 2013 PAPER AND MARK SCHEME!!!!!

Reply 1295

ivy96

can you retake this exam next year in summer?

Reply 1296

username1199902

TO ALL
anyone doing last min revision or cramming i suggest using the OCR specification which basically summarises everything that you MUST know for each unit you can find it here
http://www.ocr.org.uk/qualifications/as-a-level-gce-biology-h021-h421/
under "key documents" on page 16 where unit 2 starts its really useful !!!
hope i helped anyone x
GOOD LUCK GUYSS!!!!
WE CAN DO THIS WOOP :biggrin:

Reply 1297

adelinanuhija

Good luck guys :smile:

Reply 1298

Ché.

Original post by ivy96

can you retake this exam next year in summer?

Of course; you're subjected to one examination re-take.
It just the question of the impact on your application via UCAS!?
I am not too sure.... >_<

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Reply 1299

Nas.