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AQA A-level Biology Unit 1 26th May 2016

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Is there a thread for the Unit 2 retake?
Reply 221
In second last question I put 'against concentration gradient' instead of active transport, would I still get a mark?
Original post by haegrey
There seem to be two correct answers for this one....... That triglyceride is the limiting factor and that the enzyme denatured so the enzyme became the limiting factor....


Why does ph change?
More trigylcerides hydrolysed so more water produced, (trigylcerides produce 3 waters each)

Y does it not chage after 2 minutes?
All triglycerides hydrolysed
No more water being produced

Ph meter: quantitative and not subjective
Reply 223
Original post by Biffalo_
Is there a thread for the Unit 2 retake?


I cannot find it but I can make one
Original post by Balvier
For the ebola question: stating something along the lines of why some people where not infected by the diesie...

I said because they may have been vaccinated, this the dead antigens help the immune system produce memory cells thus they did not obtain the dieses


I put something along the lines of 'Those infected but did not develop a subsequent disease lacked the specific receptor protein that is complementary to the glycoprotein on the Ebola virus and the Ebola couldn't enter the cells and cause a disease.'

Not sure if I got it right though.
Original post by haegrey
It didn't go straight for a bit longer as the enzyme was added at the same stage rather the triglyceride was broken down at a slower rate. It is the q10 rule... That for every 10 degrees lowered the time taken doubles....

So did it level out above 3 ( slightly after 3) ?
Reply 226
Such an idiot 😭 put there are mitochondria in both eukaryotes and prokaryotes, I must have got confused with ribosomes damn it 😩


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Does anyone know if aqa will take into account that everyone taking this exam was an A2 student when determining grade boundaries? Otherwise wont they be really high compared to other years?
Original post by gcsekid
Why does ph change?
More trigylcerides hydrolysed so more water produced, (trigylcerides produce 3 waters each)

Y does it not chage after 2 minutes?
All triglycerides hydrolysed
No more water being produced

Ph meter: quantitative and not subjective


Does PH not change due to trigylcerides being hydrolysed to fatty acids? (which are acidic)
Original post by mariapops
Does anyone know if aqa will take into account that everyone taking this exam was an A2 student when determining grade boundaries? Otherwise wont they be really high compared to other years?


They scale based on what people got, not what circumstances there were. Whether people were A2 or not should not have anything to do with the outcome of the grade boundaries.
Original post by gcsekid
Why does ph change?
More trigylcerides hydrolysed so more water produced, (trigylcerides produce 3 waters each)

Y does it not chage after 2 minutes?
All triglycerides hydrolysed
No more water being produced

Ph meter: quantitative and not subjective


By water do you mean fatty acid? It'd make sense if you'd put fatty acids since the ester bonds between the glycerol molecule and the 3 fatty acids would've been hydrolysed by lipase ( each one with a water molecule). Fatty acids are acidic hence would lower the pH.
(edited 7 years ago)
For the factors that could cause a change in FEV question, did you have to list the implications the change in structure would have? I only put "Formation of scar tissue" and "Loss of elasticity in the lungs" without explaining anything.
such a b**ch of a paper smh aqa, meant to be nice to us resitters we're the stupid ones
Original post by CourtlyCanter
By water do you mean fatty acid? It'd make sense if you'd put fatty acids since the ester bonds between the glycerol molecule and the 3 fatty acids would've been hydrolysed by lipase ( each one with a water molecule). Fatty acids are acidic hence would lower the pH.


No I mean water, because water is released from hydrolysis of trigylcerides. In a triglyceride theres already three fatty acids so they would have no net change after being hydrolysed coz theres atill only three. However there is addition of water which is only present after hydrolysis
Original post by ellleanor
Yep:smile:


is this right I put this too?
Original post by CourtlyCanter
By water do you mean fatty acid? It'd make sense if you'd put fatty acids since the ester bonds between the glycerol molecule and the 3 fatty acids would've been hydrolysed by lipase ( each one with a water molecule). Fatty acids are acidic hence would lower the pH.


i wrote the same as you but i have googled it and the water thing is correct too
'When an acid is diluted by adding water to it the concentration of H+(aq) ions decreases. If the concentration of H+(aq) ions decreases the pH will increase. pH is a measure of H+(aq) ion concentration.'
Original post by Studious_Student
For the factors that could cause a change in FEV question, did you have to list the implications the change in structure would have? I only put "Formation of scar tissue" and "Loss of elasticity in the lungs" without explaining anything.


I don't think you need a explanation
(Original post by merlin444)70 Ribosomes for Mitochnodria as a reason for prokaryote ? even though everyone else put double membrane!I read up on a website this morning that had a paragraph about something like this and I just put prokaryotic cells do not have mitochondria yet they are still able to respire aerobically.(I thought that was enough to imply that prokaryotes could do what a mitochondria does. The website says 'Mitochondria are very similar to bacteria and are thought to have originated from bacteria. This points you to the answer: bacteria produce ATPs the same way mitochondria do, with the oxidation machinery place in their plasma membrane (analogous to the mitochondrial membrane).' )

My Answers are really similar to yours on all 4. questions

On Mitochnondria -I think in reality it will be a case if you mention anything realistic, such as double membrane or matrix or whatever you will get a mark for sure.

But these are merely similarities. The question asked why scientists first though were related and book mentions svedborg constant w.r.t ribosome's, this why scientists originally though they originated from prokaryotes.

Anyway now bored myself ! - good luck everyone!
Original post by Anam
Did anyone put a mitochondria comes from prokaryotic cell as it had circular dna in it?

I put this
Original post by yourmatej
such a b**ch of a paper smh aqa, meant to be nice to us resitters we're the stupid ones


That comment made my dayπŸ˜‚πŸ˜‚πŸ˜‚πŸ˜‚πŸ˜‚

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