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AS Biology Resit Unit 1 AQA MAY 14th 2012!

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    what did you guys write for the question on why people with coelic disease cant absorb products of digestion?

    i started writting things about active transport and how they dont have any mitochondria to make atp, is this write?
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    (Original post by lmacknold20)
    what did you guys write for the question on why people with coelic disease cant absorb products of digestion?

    i started writting things about active transport and how they dont have any mitochondria to make atp, is this write?
    It said in the passage that their microvilli are damaged, so i put reduced surface area means that the products of digestion cant absorb.
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    (Original post by bobmill)
    the one that asked why the water level was higher in ph8 than in ph2?
    oh yeah sorrry! higher water level not concentration!!
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    that was for the question before as the was two. the question before was about facilatated diffusion thats where i said about the microvilli being damaged
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    (Original post by nk93x)
    oh yeah sorrry! higher water level not concentration!!
    haha, for that one i put the amalase (enzyme) is not denatured unlike ph2, it hydrolises down the starch into maltose, this lowers the water potential of the water in the tube causing water to move in from outside the tube into the bag through osmosis to even out the water potentials.
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    oh yh you guys there was two questions on the diaphram which confused me cause those questions are usually easy but they gave you two, the first one was to describe the shape, this was two marks, then the second you had to explain how air moves in and part c was how does air from the alveoli move into the blood.

    what did you guys write?
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    (Original post by lmacknold20)
    that was for the question before as the was two. the question before was about facilatated diffusion thats where i said about the microvilli being damaged
    I don't remember the one about active transport :-/ It wasnt the one about cyanide was it?
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    (Original post by bobmill)
    haha, for that one i put the amalase (enzyme) is not denatured unlike ph2, it hydrolises down the starch into maltose, this lowers the water potential of the water in the tube causing water to move in from outside the tube into the bag through osmosis to even out the water potentials.
    ahhh of course that sounds so simple now! I completely wrote about the wrong thing
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    (Original post by lmacknold20)
    oh yh you guys there was two questions on the diaphram which confused me cause those questions are usually easy but they gave you two, the first one was to describe the shape, this was two marks, then the second you had to explain how air moves in and part c was how does air from the alveoli move into the blood.

    what did you guys write?
    For describe its shape i wrote "it contracts down and flattens out"

    then for how air moves in i put "the diaphragm contracting down lowers the air pressure in the thoratic cavity and therefore the lungs, this causes the air pressure inside the lung to be lower than the atmosphere so the air is 'sucked' in to even out the air pressures"

    for part C i put "moved through the alveoli epithelial cells then through the capillary epithelial by diffusion down the concentration gradient"
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    (Original post by nk93x)
    ahhh of course that sounds so simple now! I completely wrote about the wrong thing
    Haha, i might not be right. Its just what i put :P
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    (Original post by bobmill)
    for part C i put "moved through the alveoli epithelial cells then through the capillary epithelial by diffusion down the concentration gradient"
    AQA are really picky in biology when it comes do describing that so they might take a mark off for the stuff not written in bold. You'd have to say oxygen diffused through the epithelial cell wall of alveoli, then diffuses through endothelial cell wall of capillary into bloodstream down a concentration gradient.
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    (Original post by F1reF0x)
    AQA are really picky in biology when it comes do describing that so they might take a mark off for the stuff not written in bold. You'd have to say oxygen diffused through the epithelial cell wall of alveoli, then diffuses through endothelial cell wall of capillary into bloodstream down a concentration gradient.
    Damn i knew i hadn't written it quite right!

    I found that question one of the harder ones, hopefully i still get 1 of the 2 marks
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    Did this exam today also and REALLY stressing about it. i got a d in the january paper and i found this one much harder. What was the did you guys write for the question(s) on Cyanide?? Explaining how it affected mitochondrion... :confused:
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    (Original post by biology.psychology)
    Did this exam today also and REALLY stressing about it. i got a d in the january paper and i found this one much harder. What was the did you guys write for the question(s) on Cyanide?? Explaining how it affected mitochondrion... :confused:
    The one describing the graph or the one explaining why the uptake of sodium ions was less?
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    Also, in which way did the question where you had to work out the Uptake Rate of the sodium ions work?
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    (Original post by bobmill)
    The one describing the graph or the one explaining why the uptake of sodium ions was less?
    Both really..
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    Yeah, I was a bit hesitant towards explaining the question as to why peptide bonds could not be moved into epithelial cells of small intestine from lumen by facilitated diffusion.

    Was it a mark for saying that the peptide bonds were too large (1 mark?) to diffuse via carrier protein (another mark>?), and that another reason may have been that peptide bonds can't move by facilitated diffusion against their concentration gradient from lumen of small intestine into epithelial cells of small intestine. (1 mark?).

    Only question I was unsure of really.
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    (Original post by biology.psychology)
    Also, in which way did the question where you had to work out the Uptake Rate of the sodium ions work?
    (Original post by biology.psychology)
    Both really..
    to work out the sodium ion update i did 10 (the starting concentration) - 4 (the end concentration at 30 minutes) which was 6.

    so the change was 6 units over 30 minutes, so 6/30= 0.2 (as the units where units per minute)

    for describing the graph i just said it only up took 1.4 or 1.6 units before not up taking any more, staying constant.

    for the exmplaining why the update was lower with cyanide i put: "the cyanide stops the production of ATP by the mitochondria, ATP is needed for active transport. sodium ions are brought in using sodium-potasium pump which requires ATP to function, so without ATP fewer sodium ions can be absorbed."

    dont think i got it 100% right though :-/
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    (Original post by F1reF0x)
    Yeah, I was a bit hesitant towards explaining the question as to why peptide bonds could not be moved into epithelial cells of small intestine from lumen by facilitated diffusion.

    Was it a mark for saying that the peptide bonds were too large (1 mark?) to diffuse via carrier protein (another mark>?), and that another reason may have been that peptide bonds can't move by facilitated diffusion against their concentration gradient from lumen of small intestine into epithelial cells of small intestine. (1 mark?).

    Only question I was unsure of really.
    I said that they where were also insoluble? not sure if correct though
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    (Original post by bobmill)
    to work out the sodium ion update i did 10 (the starting concentration) - 4 (the end concentration at 30 minutes) which was 6.

    so the change was 6 units over 30 minutes, so 6/30= 0.2 (as the units where units per minute)

    for describing the graph i just said it only up took 1.4 or 1.6 units before not up taking any more, staying constant.

    for the exmplaining why the update was lower with cyanide i put: "the cyanide stops the production of ATP by the mitochondria, ATP is needed for active transport. sodium ions are brought in using sodium-potasium pump which requires ATP to function, so without ATP fewer sodium ions can be absorbed."

    dont think i got it 100% right though :-/
    I think i divided 30 by six to give 5 rather than vice versa, oops.

    Phew thankfully we answered similarly on the explaining one.

    There a appears to be an unofficaly mark scheme on here so i dont feel too bad about my performance now!!lol

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