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AQA BIOL1 Biology Unit 1 Exam - 16th May 2011

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The question with the agar plate... what was it asking for again???

All i remember is chosing the one with the biggest diameter.
what did everyone write for the question for explaining why the rate of reaction decreased from 30-50 degreees?
Original post by Reminisce
I'm pretty sure that its 30 or so because you need the maximum rate temperature wise for large enough clear areas (distinct) for more reliable results and to draw a more reliable conclusion. Storage was for the whole point of allowing time for the protease to perform its function rather than reducing its activity.


Yeah because if it was lower than 30 it would be too slow. If it was higher it would just denature.
& does anyone know when the mark scheme will be released?
-Sigh- you quoted the troll. He might return to once again feed.
Original post by xkate1019x
what did everyone write for the question for explaining why the rate of reaction decreased from 30-50 degreees?


Denature.
Hydrogen bonds break.
Tertiary structure changes
Active site changes
Enzyme substrate complex cant form.
So rate of reaction decreases.
(edited 12 years ago)
Original post by xkate1019x
what did everyone write for the question for explaining why the rate of reaction decreased from 30-50 degreees?


Simple denaturing of enzyme, obviously with more detail. :smile:
Reply 1467
Original post by Emily90
Oh and what did people put for working out the beats per minute and the heart calculation one? Basically the maths questions!


You divide 60 seconds (1 minute) by the total time of the cycle given to you inn the table which was 0.7 and the answer should be 86 because i rounded 85.7 as it is not correct to say 85.7 heart beats per minute :biggrin:
Original post by Limitless
Denature.
Hydrogen bonds break.
Tertiary structure changes
Active site changes
Enzyme substrate cant form.
So rate of reaction decreases.


Yet it was a 2 mark question. :biggrin:
Original post by xkate1019x
what did everyone write for the question for explaining why the rate of reaction decreased from 30-50 degreees?


Said the temperature increased caused the ionic and hydrogen bonds to break causing the 3d tertiarry structure to change shape and active site changes shape so is no longer perfectly complimentry to sumbstrate so rate decreases as fewer substrate-enzyme complexes formed.
Original post by Baha
You divide 60 seconds (1 minute) by the total time of the cycle given to you inn the table which was 0.7 and the answer should be 86 because i rounded 85.7 as it is not correct to say 85.7 heart beats per minute :biggrin:


You can also say 85.
Original post by Limitless
Denature.
Hydrogen bonds break.
Tertiary structure changes
Active site changes
Enzyme substrate cant form.
So rate of reaction decreases.


Thanks, i really didn't know what to write here, so how many marks do you think i'd for saying the enzymes start to denature, so there is less active sites available for the substrates to bind to, lowering the rate of reaction (it was worth 2/3 marks i think)
Original post by Wick3d
Yet it was a 2 mark question. :biggrin:


****...
Original post by xkate1019x
Thanks, i really didn't know what to write here, so how many marks do you think i'd for saying the enzymes start to denature, so there is less active sites available for the substrates to bind to, lowering the rate of reaction (it was worth 2/3 marks i think)


Probably full marks I wrote the same as you I think.
Reply 1474
Original post by swiftylol
The question with the agar plate... what was it asking for again???

All i remember is chosing the one with the biggest diameter.


It asked you to determine the optimum PH for the enzyme to work out as well as the temperature from the graph given on the previous page.
Reply 1475
You are kidding...it was that simple! lol oh dear....but thank you! What was that heart cycle one again?
Original post by Wick3d
Yet it was a 2 mark question. :biggrin:


AQA just being messed up again. Award 6 mark for vague ones. 1 mark for those which require lots of detail. Make one mistake wrong and you lose 1/2 the marks for the question.
Original post by Limitless
****...


That's what I thought when I checked my answer. :biggrin:

It was like I answered a 5 mark question!
Emohysema question was four marks, so i spoke about less elasticity in lungs, hard to force air out of alveoli, reduced conc gradient for diffusion and i also said about reduced surface area of alveoli meaning that there is a slower rate of diffusion thoughts?

also what was the exact wording of the last 6 marks quetion?
Reply 1479
Grade boundaries (for an a) will not be 50! Who ever wrote that is probably the most retarded person ever

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