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    (Original post by Maham88)
    what detects low and high glucose levels in the blood ?
    The alpha and beta cells in the islets of langerhans
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    (Original post by maisie__x)
    1. The asending limb is permeable to sodium chloride ions, these leave the tubule by diffusion at the bottom and further up by active transport and are reabsorbed into the tissue fluid.

    2.Because there is now a higher concentration of sodium and chloride in the tissue fluid than in the tubule this creates a concentration gradient between the tissue fluid and tubule fluid.

    3. The descending limb is permeable to water but impermeable to sodium chloride. Because of the created concentration gradient, water diffuses out of the descending limb by osmosis and is reabsorbed into the tissue fluid.

    4.This creates a concentrated tubule fluid so minimize water loss. As the fluid flows through the collecting duct, more water can be reabsorbed into the tissue fluid and then into blood capillaries by altering the walls permeability to water (this is osmoregulation)
    Okay, just written this out. Thank you
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    Anybody got any predictions on the paper? been looking but no one is replying
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    (Original post by domcandrews)
    Same i'm getting mostly B's,got 2A's so far, I need an A overall aswell but for econ! Just hoping for 2 good papers, but my feeling seems otherwise especially for f215, can just imagine that 8 marker on timber production or something that i'm not interested in like a 9 marker on Galapagos bullshiit. Good luck for medicine, which uni if you don't mind me asking?
    Aw let's hope we get the grades! I'm worried if I just completely misinterpret a 9 marker or do something stupid. :/
    I've got an offer from Liverpool which is AAA and I have no back up haha since it was my only offer.

    (Original post by Cara_rose)
    I've been getting straight A's is there any topic where you've been losing your marks in particular? I would be happy to help
    Thanks that's really nice of you actually, I'll PM you if I find something major haha.
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    why is the theoretical max yield of ATP per molecule of glucose hardly reached in aerobic respiration ?
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    What's the difference between an ectotherm and endotherm?
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    (Original post by joshuajh1707)
    Anybody got any predictions on the paper? been looking but no one is replying
    Will be looking over all the papers, making a list of topics of the spec points that haven't come up at all/recently, most likely tomorrow now. But in general I think you should revise everything, just can't tell, Will be tomorrow, when I get time to make a document or something

    hope this helps
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    (Original post by WishIHadRevised)
    Aw let's hope we get the grades! I'm worried if I just completely misinterpret a 9 marker or do something stupid. :/
    I've got an offer from Liverpool which is AAA and I have no back up haha since it was my only offer.



    Thanks that's really nice of you actually, I'll PM you if I find something major haha.
    Yeah totally agree, the drop in grade is huge if you do misinterpret something!
    Congrats on the offer firstly, it takes a lot to get a med offer these days! i'm sure you'll get the grades, getting an offer med must be major motivation!!
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    (Original post by domcandrews)
    Will be looking over all the papers, making a list of topics of the spec points that haven't come up at all/recently, most likely tomorrow now. But in general I think you should revise everything, just can't tell, Will be tomorrow, when I get time to make a document or something

    hope this helps
    Thank you, I have revised everything and was just looking for some extra items to have a good look at and refresh my memory the morning if the exam.
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    (Original post by baffledchick)
    What's the difference between an ectotherm and endotherm?
    Ectotherm is an organism that relies on external sources of heat to regulate its body temperature whereas an endotherm is an organism that uses internal sources of heat to maintain its body temp
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    (Original post by baffledchick)
    What's the difference between an ectotherm and endotherm?
    An endotherm uses internal sources of heat such as that from metabolism/ respiration to maintain its body temperature within strict limits. Examples are birds and mammals

    An ectotherm relies on external sources of heat to regulate its body temperature. Examples are arthropods, insects and reptiles
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    (Original post by joshuajh1707)
    Thank you, I have revised everything and was just looking for some extra items to have a good look at and refresh my memory the morning if the exam.
    Yeah that was exactly my plan, they're obvusly not going to test the whole syllabus, they will weight more towards a few areas, now it's just how accurate we can predict, but yeah good idea to have sound knowledge of all the spec points
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    Thank you, both ectotherms and endotherms have physiological and behavioural adaptations right? Eg Ectotherms - lizard expands its ribcage and frilled lizard uses its frill to expand surface area to absorb more heat from the sun? Locusts increase breathing rate to increase water loss when hot?
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    (Original post by kell123)
    hi guys, is it worth learning the method for measuring the rate of respiration even though its not included in the spec. many thanks
    I would say it's worth being aware of the basics of the method (just in case they throw in an application of knowledge question), although learning it until you can design it perfectly or anything is just a waste of time.
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    Can someone tell me what's the best way to revise evidence of chemi-osmosis and what's the besst way to deal with them in the exam?
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    (Original post by Maham88)
    why is the theoretical max yield of ATP per molecule of glucose hardly reached in aerobic respiration ?
    Because energy is used in the other parts of the plant (e.g. photosynthesis), and energy can be lost along the ETC, I think
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    Outline the use of biochemical tests to determine the presence of biological molecules in a solution. (5)
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    is the electron transport chain part of chemiosmosis ?
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    Can someone please explain to me local currents/circuits?? (neurones)
    Thank you
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    (Original post by HeyThereHarry)
    Outline the use of biochemical tests to determine the presence of biological molecules in a solution. (5)
    What on earth is that on about ???
 
 
 
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