not particularly. There were some things that tricked me out. Even the last page, now that I look at the mark scheme.
I just did this exam today in a mock for the jan exam. Doing this exam for the first time on 25th Jan :smile:

Reply 43

Freiheit

Original post by aedai

I guess Biology is about mastering the "suggest" questions and the mark scheme :tongue:

25th will also be my first time sitting this exam. Where the grade boundaries helpful for you when you took this mock test? For example, did the grade boundaries make the test not as difficult because you did not need as many marks to end up with a good grade still or did the boundaries seem too high still?

Reply 44

Bi0logical

Photosynthesis notes:

Photophosphorylation: Is making ATP from joining ADP and Pi together.

Cyclic Photophosphorylation:
This uses PSI (p700) only. The excited electrons pass to an electron accepter and back to the chlorophyll molecule from which they were lost. There is no photolysis of water no generation of reduced NADP, but small amounts of ATP are made which can be used in the light-independant reaction or in the guard cells.

Non-cyclic photophosphorylation:
- This involves both PSI and PSII
1) Light strike PSII exiting a pair of electrons, they leave the chlorophyll from the primary pigment reaction centre.
2) The electrons pass along a chain of electron carriers and the energy released is used to synthesise ATP.
3) Light has also struck PSI and a pair of electrons have been lost
4) These electrons aswell as 2H+ from the photolysis of water occuring at PSII join NADP, which becomes reduced NADP.
5) The electrons from oxidised PSII replace the electrons lost by PSI.
6) Electrons from photolysis of water replace those lost by oxidised chlorophyll at PSII.
7) Protons from photolysed water take part in chemiosmosis to make ATP and are then captured by NADP, the stroma. They will be used in the light-independant reaction.

Reply 45

pinkprincess123

hey guys, you know the OCR exam cafe CD that goes with the textbook? is there any way that i can work it on mac?

Reply 46

Bi0logical

Light-independant reaction occurs in the stroma.

1. CO2 from the air diffuses into the leaf through open stomata, most of which are on the underside of the leaf. It then diffuses throughout the air spaces in the spongy mesophyll and reaches the palisade mesophyll layer. Here it diffuses through the thin cellulose walls, the cell surface membrane, the cytoplasm and the chloroplast envelope into the stroma.

2. In the stroma, carbon dioxide combines with a 5 carbon compound, ribulose biphosphate, RuBP. This is a CO2 accepter, the reaction is catalysed by ribulose biphosphate carboxylase oxygenase, also known as Rubisco. RuBP becomes carboxylated ( now contains carboxyl group)

3. The product of this reaction is two molecules of a 3carbon compound called glycerate-3-phosphate. The CO2 has now been fixed.

4. GP is reduced and phosphorylated to another 3-carbon compound called Triose phosphate (TP). ATP and reduced NADP are used in this process and come from the light-dependant reaction.

5. Five out of Six molecules of TP (3C) are recycled by phosphorylation, using ATP from the light-dependant reaction, to three molecules of RuBP (5C).

How the products of the calvin cycle are used?
- Some GP can be used to make amino acids and fatty acids
- Pairs of TP molecules can combine to form hexose sugars such as glucose.
- Some glucose molecules may be isomerised to form fructose.
- Glucose and fructose may combine to form sucrose (the sugar translocated in phloem)
- Hexose sugars can be polymerised to form carbohydrates (polysacharides) such as cellulose and starch.
- TP can also be converted to glycerol which can combine with fatty acids formed by GP to make lipids.

Reply 47

montoya93

Original post by pinkprincess123

hey guys, you know the OCR exam cafe CD that goes with the textbook? is there any way that i can work it on mac?

if you find a way, could you do me a massive favour and put up a download link to the part where it explains the wording of exam questions please? :smile:

Reply 48

Bi0logical

Original post by montoya93

if you find a way, could you do me a massive favour and put up a download link to the part where it explains the wording of exam questions please? :smile:

is the CD even good? I've never used it. I just use the Heinemann/OCR Revision Guide

Reply 49

montoya93

Original post by Bi0logical

is the CD even good? I've never used it. I just use the Heinemann/OCR Revision Guide

What I'm asking for is quite useful as it expains what they're looking for when they say 'explain'/'outline' etc.. I always end up writing more than I need to. Some of it is a bit useless though.

Reply 50

Sailingslipelick

Can't believe that revision time has come around so fast

Reply 51

Bi0logical

Original post by Sailingslipelick

Can't believe that revision time has come around so fast

Tell me about it! How is you're revision going?

Reply 52

Princess Kawaii

The stretch and challenge questions in the text book are all right and fairly easy to do...but
the suggest questions that actually come up in the exams are so difficult :frown:

Reply 53

Bi0logical

Original post by Princess Kawaii

The stretch and challenge questions in the text book are all right and fairly easy to do...but
the suggest questions that actually come up in the exams are so difficult :frown:

I just find it hard to remember all the content -_-

Reply 54

Princess Kawaii

Original post by Bi0logical

I just find it hard to remember all the content -_-

True...It is hard ...soo much content to learn compared to last year...and when it comes to the June unit f215 I don't know what I'm going to do...that unit is HUGE!! :eek:

I would say take it bit by bit...you know take each module and learn the important bits then move on to the next...n then re-visit the previous module briefly to make sure its still there in your head :biggrin:

Reply 55

Sailingslipelick

Original post by Bi0logical

Tell me about it! How is you're revision going?

Not as great as last year. Last year, the revision guide got me through both exams, this year I'm going through the textbook. So much stuff to learn!! And of course only snippets of it actually come up.
i hate those suggest questions though! There were so many in that june 11 paper. They're not bad, but you just have to think outside the box and that always unnerves me a little b/c I always think I am going off at a wrong tangent.
But we will try and rip that paper apart in jan :run:

How's your revision going??

Reply 56

Bi0logical

Original post by Sailingslipelick

How's your revision going??

Yeah I know what you mean, not bad but there's just too much stuff to learn like the cycles, ornithine, krebs, calvin etc! they confuse me when I learn them all! :/