AQA A2 Biol4 January 2012 pre- exam discussion

Original post by EffKayy

probably not. \:

haha

Okay, I just asked because there was half a page on it in the CGP revision guide.

Reply 781

AmbitiousMedic

Original post by barzy_j

yeah thats where I'm coming from too

Re-read your initial question and noticed you mentioned organisms. I can understand now that you would class one tree as one organism which has lots of organisms feeding on it. Then your question isn't really valid, perhaps a similar question would relate it to the drawbacks of using a pyramid of numbers in this situation.. or your initial question would need to change to biomass/energy as opposed to the number..

(edited 12 years ago)

Reply 782

AmbitiousMedic

Original post by Erotas

Okay, I just asked because there was half a page on it in the CGP revision guide.

Are we expected to know the different stages of the model, or would it be an interpretation question if asked :confused:

Reply 783

Original post by AmbitiousMedic

Are we expected to know the different stages of the model, or would it be an interpretation question if asked :confused:

I'm not sure which is the reason why I asked. I'm just going to read through it so I have something to write in case it is asked. But I don't think it can be asked about in detail.

Reply 784

AmbitiousMedic

Original post by Erotas

I'm not sure which is the reason why I asked. I'm just going to read through it so I have something to write in case it is asked. But I don't think it can be asked about in detail.

Ah okay, I can't see them really asking us to recall the whole model from scratch to be honest.. I'll just go over it like you so I have something to write if asked :tongue:

Reply 785

Original post by Erotas

Okay, I just asked because there was half a page on it in the CGP revision guide.

CGP books sometimes contain information that we do not need to know. This is why i refused to buy one this year. My friend has it and it talks about protons being pumped across a membrane in photosynthesis and I'm sure we do not need to know that and if we start talking about it in the exam, we won't get extra marks.

Please, do not confuse us :s-smilie:

(edited 12 years ago)

Reply 786

farrar

worlds easiest for anyone who did AS Geography.. It's literally the same stuff (especially if you did the food section)

Reply 787

Original post by Rahmeh.

CGP books sometimes contain information that we do not need to know. This is why i refused to buy one this year. My friend has it and it talks about protons being pumped across a membrane is photosynthesis and I'm sure we do not need to know that and if we start talking about it in the exam, we won't get extra marks.

Please, do not confuse us :s-smilie:

Sorry, I wasn't trying to confuse you. But just so you know, I have been taught about the DTM at school, and I have seen a 1 or 2 mark question on it before so I'm still going to go over it. Better to be safe than sorry.

Reply 788

farrar

Original post by AliAli_264

Can someone give me a brief description of oxidative and substrate level phosphorylation, i've got notes on it but i want it breif. my notes waffle too much lol

Substrate-level phosphorylation occurs during Glycolysis and the Kreb's Cycle and involves the physical addition of a free phosphate to ADP to form ATP. Oxidative phosphorylation, on the other hand, takes place along the electron transport chain, where ATP is synthesized indirectly from the creation of a proton gradient and the movement of these protons back accross the membrane through the protein channel, ATP synthase. As the protons pass through, ATP is created.

Reply 789

Original post by Rahmeh.

CGP books sometimes contain information that we do not need to know. This is why i refused to buy one this year. My friend has it and it talks about protons being pumped across a membrane is photosynthesis and I'm sure we do not need to know that and if we start talking about it in the exam, we won't get extra marks.

Please, do not confuse us :s-smilie:

errr, actually we do need to know about this (chemiosmosis) and how ATP is formed..

Reply 790

chill543

isnt that in repiration anyways on electron transport chain?

Reply 791

Original post by EffKayy

errr, actually we do need to know about this (chemiosmosis) and how ATP is formed..

yes..in respiration. NOT photosynthesis :smile:

Reply 792

Original post by chill543

isnt that in repiration anyways on electron transport chain?

The electron transport chain is involved in the light-dependent stage for photosynthesis too :smile:

Reply 793

Original post by Rahmeh.

yes..in respiration. NOT photosynthesis :smile:

Actually, the electron transport chain is involved in photosynthesis too(light dependent) and the proton gradient thing does occur in there..

Reply 794

chill543

oh ye, haha i just had the vision of H+ being pumped out of a membrane then returning by ATP synthase, silly ol me :P

Reply 795

Original post by EffKayy

The electron transport chain is involved in the light-dependent stage for photosynthesis too :smile:

Yes you are right but we don't need to talk about chemiosmosis in photosynthesis [It's not in the specification]

(edited 12 years ago)

Reply 796

chill543

does phot have an atp synthase? should i whrite about it if it comes up btw?

Reply 797

Original post by Rahmeh.

Yes you are right but we don't need to talk about chemiosmosis in photosynthesis

But you need to know how ATP is formed in the light dependent stage, so talking about pumping of H+ etc. (prev 5marker)

Reply 798

Original post by chill543

does phot have an atp synthase? should i whrite about it if it comes up btw?

The ATP synthase and protons being pumped doesn't seen to give you the mark when writing about photosynthesis so don't waste your time writing about it there. Do still write about it with regards to respiration though.

Reply 799