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Today's Mammalian Physiology (OCR) watch

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    I thought it was alright tbh. Its wasn't much of the hard stuff and loads of marks for graph interpretation and stuff. Last question was a bit weird mind.
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    I'd damn happy with that, was a God send.

    Though for the saturated fats question what did you put? Some people seemed to put the reduction in number of receptors on the membrane means that you need more LDLs in the blood to have the same effect, so LDL levels raise (I put that).

    Others seemed to put that reduction in numbers of receptors means that less LDLs are absorbed and so the blood levels of LDLs raise, and the cells get less.

    What did everyone put for this, and what do they consider is correct in hindsight?

    Also, for the pain reception question, that was weird....I talked about action potentials being created because of depolarisation then hyperpolarisation, explaining it all, but we don't really know how pain receptors work.....
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    (Original post by cougem)
    I'd damn happy with that, was a God send.

    Though for the saturated fats question what did you put? Some people seemed to put the reduction in number of receptors on the membrane means that you need more LDLs in the blood to have the same effect, so LDL levels raise (I put that).

    Others seemed to put that reduction in numbers of receptors means that less LDLs are absorbed and so the blood levels of LDLs raise, and the cells get less.

    What did everyone put for this, and what do they consider is correct in hindsight?

    Also, for the pain reception question, that was weird....I talked about action potentials being created because of depolarisation then hyperpolarisation, explaining it all, but we don't really know how pain receptors work.....
    For starters I thought the LDL question was eerily simple, they basically told you the answers in the questions. If fatty acids reduce the LDL receptor production and recycling then once an LDL molecule has been broken down by a receptor the receptor is gone, therefore over time LDL levels are going to increase, was it anymore complicated than that???

    For the pin question I remembered something about Pacinian corpuscle cells in the skin which sense pressure (i think?), and just wrote about what happens with them to generate an action potential etc etc.

    The last question was a bit dodgy soley because I couldn't think of enough points, the book I have no way goes into 7 marks worth of detail of that process, errrg. The eye question was a bit unpredictable too, so who knows.

    Overall I liked it muchly, good paper.

    Answers for the first question? and the Alzheimer's question?
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    i thought it was sooooooo hard!It was a really long paper and it had wierd questions in it! Thing is, i usually get A in biology papers but my friend who usually gets D/E thought it was easy! damn it!
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    (Original post by kingpong)
    For starters I thought the LDL question was eerily simple, they basically told you the answers in the questions. If fatty acids reduce the LDL receptor production and recycling then once an LDL molecule has been broken down by a receptor the receptor is gone, therefore over time LDL levels are going to increase, was it anymore complicated than that???
    The receptors don't break down the LDLs, they let the cells absorb them. You could argue that without the cells absorbing them so much, levels raise. But you could also argue that the body compensates my making more LDLs to increase the amount the body gets. It might need to do this because cells need a constant supply of cholesterol. The more LDLs therefore raises the concentration in the blood -> Atherosclerosis.

    For the pin question I remembered something about Pacinian corpuscle cells in the skin which sense pressure (i think?), and just wrote about what happens with them to generate an action potential etc etc.
    These were pain receptors firing though, not pressure receptors?
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    (Original post by cougem)
    The receptors don't break down the LDLs, they let the cells absorb them. You could argue that without the cells absorbing them so much, levels raise. But you could also argue that the body compensates my making more LDLs to increase the amount the body gets. It might need to do this because cells need a constant supply of cholesterol. The more LDLs therefore raises the concentration in the blood -> Atherosclerosis.
    Yes, but what I put was the receptors were required for the hepatocyte to break down the LDL, obviously the receptor aren't doing it themselves. If you don't have receptors LDL levels are only going to rise.

    These were pain receptors firing though, not pressure receptors?
    Who knows. It was the best I could think of! Feck me if I know which cells are pain receptors!
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    O M G I COULD NOT DO ANY OF THE PAPER. ONLY BIT I COULD DO WERE THE 2 7 MARKERS and i usually get A's theres NO WAY i got over 50%, we hadnt bin taught 90% of what was on the paper, including thr last Q, I F*CKED UP BIG STYLE, no-one at my school could do it, all the questions were WIERD and i revised the whole book and still couldnt do it. im screwed bye bye bye uni like im not even jokin here i was crying at the end of the exam. if only my school let me do the env biology option
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    I know, we hadn't covered half of it either, but I just crammed from the text book constantly for 3 days and this morning. If I hadn't I doubt I'd have got 50%

    All the teachers at ours seemed to be teaching this from syllabuses about 30 years old, we didn't get told about co transport or anything, or the structure of rods and cones, only their uses and so on. Half the stuff was missed out, yet we went in 10 times more detail than needed on the Ornithine cycle.

    And hey cmon person above, I'm sure you're exaggerating. Things seem SOOO much worse coming out of the exam, you'll feel better soon I'm sure.
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    lol didnt see yer thread here

    I thought the exam was alrite. Its easier than majority of the past papers I've done.
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    (Original post by emzie)
    O M G I COULD NOT DO ANY OF THE PAPER. ONLY BIT I COULD DO WERE THE 2 7 MARKERS and i usually get A's theres NO WAY i got over 50%, we hadnt bin taught 90% of what was on the paper, including thr last Q, I F*CKED UP BIG STYLE, no-one at my school could do it, all the questions were WIERD and i revised the whole book and still couldnt do it. im screwed bye bye bye uni like im not even jokin here i was crying at the end of the exam. if only my school let me do the env biology option
    hey don't worry about it too much, Mammalian Physiology usually lowers the mark to get a good grade anyways. I think it was something like 68% to get an A last year?

    It's unifying concepts I'm ******** myself about, coz that was sooooo damn difficult to the maximum
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    In january it was 64/90 for an A (71%) and 54/90 for a B, (60%) so they basically lowered it by a grade.

    But I think this was easier than January's....still that's just my opinion.
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    im not exagerrating, I would say if I thought I did ok (I found central conepts and unifying quite easy)

    I hope the grade boundaries get lowered, I was on track for an A overall, now I think i'll be lucky to scrape a B, I just want my AAB so that I can get into uni
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    I did all the past papers and found all of them WAY easier than this one!! i'm so annoyed!
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    Oooh, good stuff, hopefully the grade boundaries get lowered if everyone thought it was hard. UC was a ***** compared to this.

    Come on though, it wasn't that bad, the first question was relatively simple with all the Alzheimer's stuff surely?
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    (Original post by kingpong)
    Oooh, good stuff, hopefully the grade boundaries get lowered if everyone thought it was hard. UC was a ***** compared to this.

    Come on though, it wasn't that bad, the first question was relatively simple with all the Alzheimer's stuff surely?
    yeah the first question with the 7 mark intepreting one is really comfortable and nice. And what about the last 7 mark question? that was really straight-forward although I had to keep trying to think of more to write, coz the paragraph pretty much summarised it all, but still it was really do-able.

    Unifying Concept is a ***** ***** *****. I agree totally with u kingpong
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    (Original post by ResidentEvil)
    yeah the first question with the 7 mark intepreting one is really comfortable and nice. And what about the last 7 mark question? that was really straight-forward although I had to keep trying to think of more to write, coz the paragraph pretty much summarised it all, but still it was really do-able.

    Unifying Concept is a ***** ***** *****. I agree totally with u kingpong
    Run me through what your 7 markable points would have been for the last question if you can be arsed. That was the only one that ****ed me over, my MP book no way goes into enough detail for that.
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    Can someone please tel me how ruminants such as cows create anaerobic conditions in their stomachs if they swallow air????
    Guh this question bugged me
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    UC was fine but CC was a ***** because I thought I'd finished when I hadn't due to a blank page, then had to do 5 pages in 20 mins.

    For the last q I said:

    ACh -> Na+ channels open (resting pd of -65mV present due to 3Na+ out, 2K+ in, K+ leakage and organic anion in centre)
    Na+ floods in -> +40mV p.d
    Na+ closes and K+ floods out -> -75mV pd with hyperpolarisation
    This action potential propagates down the membrane down the T(transverse) tubules
    This action potential results in the sarcoplastic reticulum (which usually is only pumping Ca2+ ions in by active transport) to open its calcium channels
    Calcium floods out of sarcoplasmic reticulum down conc gradient
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    (Original post by mc_remedi)
    Can someone please tel me how ruminants such as cows create anaerobic conditions in their stomachs if they swallow air????
    Guh this question bugged me
    Yeh that was tricky, I said maybe it happens in solution and that gasses formed passes up through the throat and out, but that was a guess
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    (Original post by kingpong)
    Run me through what your 7 markable points would have been for the last question if you can be arsed. That was the only one that ****ed me over, my MP book no way goes into enough detail for that.
    ****ed u over? that surely wasn't a problem question but just slightly difficult to write 7 points. This was my setup:
    - I first described just a short paragraph about motor neurones releasing neurotransmitter into the neuromuscular junction
    - then it binds to glycoprotein receptors on the sarcolemma
    - sodium channels open, and ions flood in to depolarise
    - action potential is set up along the t-tubules
    - stimulates the muscle cells' sarcoplasmic reticulum to become permeable to calcium ions/calcium channels open
    - ca+ ions rush out from the cisternae
    - diffuses amongst the fibrils
    - therefore muscle contraction
 
 
 
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