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

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Only a few days til the exam! :s-smilie:

How is everyone feeling about the exam and how is revision going? I've just a few things to go over from the health section :smile:

Really hoping for a biological molecules heavy paper which it should be :smile:

Reply 361

imconfused

Original post by own

There are some called 'human health and disease' and I think 'environmental biology' they are all old specification from ~2000-->2008 so you have to be picky and see which questions are actually still relevant, but its good practice :smile:

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okay thanks :biggrin:

Reply 362

Gotzz

Original post by AtotheT

Hey dude, they're not covalently bonded. Cellulose molecules form glysocidic bonds with each other and this is an example of a condensation reaction because a water molecule is released. Also, they are joined together by hydrogen bonds because their hydroxyl groups are antiparallel. Hydrogen bonds form between the anime and carboxyl groups :smile:

My bad, it seems I mixed cellulose with collagen :colondollar:

Okay so cellulose:
Hydrogen bonds between chains due to the projecting OH groups.
Collagen:
Covalent bonds (cross-links) between molecules.
Also, cellulose molecules don't form glycosidic bonds with each other, it's the glucose monomers that do :smile:

Reply 363

Gotzz

Original post by wndms

Thank you!

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What I told you was wrong, sorry :colondollar:

I've edited my post.

Reply 364

Gotzz

Original post by own

Yes they are covalently bonded, glycosidic is just the specific name for the bond. Like in DNA, the back bone is made up of phosphodiester bonds, however the bonding is actually just covalent between a phospate group and a sugar...just fancy names :smile:

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Yeah the bonds between the monomers are covalent but I was talking about bonds between the actual chains, which in cellulose, are hydrogen bonds.

Reply 365

Minz

What structure does collagen have? Is it quaternary or just completely different structure?

Reply 366

Munrot07

Original post by Minz

What structure does collagen have? Is it quaternary or just completely different structure?

Quaternary :smile:

Reply 367

Blashnet

Original post by Minz

What structure does collagen have? Is it quaternary or just completely different structure?

What is quaternary?

I don't understand it :'(

Reply 368

Blashnet

Has anyone done the January 2011 paper?

Reply 369

Gotzz

Original post by Blashnet

What is quaternary?

I don't understand it :'(

It just means that the protein is made up of more than one polypeptide chain. So collagen is made up of 3 chains and haemoglobin is made up of 4. :smile:

Reply 370

Gotzz

Original post by Blashnet

Has anyone done the January 2011 paper?

Yes, I have

Reply 371

Blashnet

Original post by Gotzz

Yes, I have

how did you find it?

Reply 372

trrr

Does anybody have notes on biodiversity?

Reply 373

thecurlymedic48

I really hope this paper isn't as strong on biodiversity and evolution, i struggle with that but

Btw does nicotine cause constrictions of arterioles? Cause in the text book it says it does but i did a past paper yesterday, and it said that carbon monoxide does.

Don't they both? or is it just CO?

Reply 374

wndms

Is phagocyte a primary defence?

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Reply 375

nevarsan

Original post by wndms

Is phagocyte a primary defence?

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No its a secondary defence

Reply 376

Gotzz

Original post by Blashnet

how did you find it?

Not too bad, I got an A (73 marks)
What about you?

Reply 377

Blashnet

Original post by Gotzz

Not too bad, I got an A (73 marks)
What about you?

I thought it was the hardest past paper, a lot of ambiguous questions!

I got 69, an A :biggrin:

Reply 378

Gotzz

Original post by Blashnet

I thought it was the hardest past paper, a lot of ambiguous questions!

I got 69, an A :biggrin:

I still have two papers to go but so far my lowest marks are on January 2013 (due to no revision) and January 2010 :P
But the grade boundaries for that paper were rather low so I guess it must have been quite difficult.