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AQA BIOL5 Biology Unit 5 Exam - 22nd June 2011 Watch

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    (Original post by parallal)
    I don't know if anyone has posted anything like this but here are some condensed notes I made. Hope they're helpful (If there is already notes then just let me know and I'll take these down)
    They're not perfect so if there's anything I missed out or anything like that let me know

    I'll add the notes on genes as soon as I'm done with them.
    Added the last three chapters on genes
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    (Original post by Eloades11)
    You'll only need 60% in this exam to get an A, that works as some encouragement, but try not to think "Oh, well, I can get 60% and get an A, I don't need to revise as much as I thought!"

    I have written 1 essay, and I got it marked at a C grade by my teacher. I haven't written an essay since -.- my teacher gave me no useful feedback and I don't know how to make it better, so why write another essay if it's just going to be the same as my last?

    Does anyone object to me writing up my essay on here so I could receive some constructive criticism?
    Really?? :eek:
    That doesn't seem much. Oh, and don't worry, I never think that anymore, after one pitiful grade
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    Thank you so much for the notes!! I'm only half way through making mine and i've run out of revision cards!!!
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    can someone please explain to me about how adrenaline and the second messenger model, cAMP etc all increase your blood glucose level
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    (Original post by parallal)
    Added the last three chapters on genes
    hey do you have condensed notes on unit4 as i am resitting, really struggling with ecology and HSW, your notes are amazing..
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    (Original post by Eloades11)
    You'll only need 60% in this exam to get an A, that works as some encouragement, but try not to think "Oh, well, I can get 60% and get an A, I don't need to revise as much as I thought!"

    I have written 1 essay, and I got it marked at a C grade by my teacher. I haven't written an essay since -.- my teacher gave me no useful feedback and I don't know how to make it better, so why write another essay if it's just going to be the same as my last?

    Does anyone object to me writing up my essay on here so I could receive some constructive criticism?
    I'm interested to see it, and I will try to help
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    (Original post by ben10)
    can someone please explain to me about how adrenaline and the second messenger model, cAMP etc all increase your blood glucose level
    basically ..
    - adrenaline acts as a 'first messenger'
    - it binds to receptors (glycoprotiens) on target cells forming a hormone-receptor complex, namely an 'adrenaline-receptor complex'
    - this hormone-receptor complex stimulates the activation of an enzyme inside the cell
    - this enzyme converts ATP into cyclic AMP
    - cyclic AMP acts as the 'second messenger'
    - cyclic AMP activates other enzymes that cause the respone, in this case the response is an increase in blood glucose level. cyclic AMP therefore activates enzymes which catalyse reactions that convert glycogen into glucose (glycogenolysis) and therefore increase the level of glucose in the blood

    i really hope thats right because thats how ive learnt it correct me if im wrong lol
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    (Original post by al_habib)
    hey do you have condensed notes on unit4 as i am resitting, really struggling with ecology and HSW, your notes are amazing..
    Sorry but no. I got rid of them after I got my results. But what exactly are you struggling with? Maybe I can help you.
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    Could I ask, how is everyone revising for the essay? Is there particiular stuff that can/cannot come up on it? Are people just practicing essay titles or are people reading over the previous units.

    Thanks.
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    ^ To practice essays my teacher gave us a big booklet of all the past exam questions and their mark schemes. So im either reading over them, or actually writing them out.


    After revising this unit alot, im actually convinced its easier than Unit 4. (Apart from the essay aspect).
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    For the synoptic essay I've been reading over past notes, but is anyone else worried about putting too much focus on this rather than on the unit 5 stuff?

    I was thinking, the synoptic essay will probably be linked in with this unit at least a little bit? I can't see an essay being purely about some of the environmental topics in unit 4. Does anyone agree?
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    (Original post by OhNo_23)
    For the synoptic essay I've been reading over past notes, but is anyone else worried about putting too much focus on this rather than on the unit 5 stuff?

    I was thinking, the synoptic essay will probably be linked in with this unit at least a little bit? I can't see an essay being purely about some of the environmental topics in unit 4. Does anyone agree?
    I hope it's not about unit4, though I have seen a question about energy in ecosystems
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    (Original post by emmaaa65)
    basically ..
    - adrenaline acts as a 'first messenger'
    - it binds to receptors (glycoprotiens) on target cells forming a hormone-receptor complex, namely an 'adrenaline-receptor complex'
    - this hormone-receptor complex stimulates the activation of an enzyme inside the cell
    - this enzyme converts ATP into cyclic AMP
    - cyclic AMP acts as the 'second messenger'
    - cyclic AMP activates other enzymes that cause the respone, in this case the response is an increase in blood glucose level. cyclic AMP therefore activates enzymes which catalyse reactions that convert glycogen into glucose (glycogenolysis) and therefore increase the level of glucose in the blood

    i really hope thats right because thats how ive learnt it correct me if im wrong lol
    that looks perfect
    thanks
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    (Original post by OhNo_23)
    For the synoptic essay I've been reading over past notes, but is anyone else worried about putting too much focus on this rather than on the unit 5 stuff?

    I was thinking, the synoptic essay will probably be linked in with this unit at least a little bit? I can't see an essay being purely about some of the environmental topics in unit 4. Does anyone agree?
    Its 25 marks. So no work you do towards it is a waste. Plus unit 5 stuff will be on the essay, so by revising unit 5 you're doing revision for both. Concentrate on unit 5 first.
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    Maybe reading over just the specification for the others units would help? That way it would rejig your memory on older topics without having to learn over previous notes?
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    does anyone know how too calibrate the gel electropherisis.. ?
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    If I post up an essay I just had a go at could someone read it and maybe suggest what sort of marks I'd have gained/where there are errors or what I could add to it?

    How long should the essay be and in what detail should each topic with it be discussed? The essay below took me about 30 minutes or so to plan and write and took up 2 1/2 sides of A4

    QUESTION: CO2 may effect organisms directly or indirectly describe and explain these effects.

    ANSWER:

    CO2 is an important carbon based molecule required for photosynthesis in photosynythetic organisms. CO2 is involved in the assmiliation of organic molecules via the calvin cycle/light independant reaction which requires CO2 to reduce ribulose biphosphate to in turn produce glycerate-3-phosphate which is reduced by reduced NADP from the light dependant reaction produce triose phosphate to achieve this. Some triose phosphate is converted into organic molecules such as glucose and some is used to reform ribulose biphosphate so that the calvin cycle can continue.

    Glucose and other organic molecules produced in this process form the basis of organic plant cells and glucose itself acts as a energy source which can be used to produce ATP which is an energy carrier molecule required to provide energy for processes such as active transport which allow the plant to absorb mineral ions required for growth.

    CO2 can have a direct affect on human and other aerobic organisms. It is a produce of respiration and is transported via the blood from respiring cells to the lungs for removal. CO2 forms an acid when dissolved in solution and therefore in blood it is acidic. If the acidicy of blood increases unless corrective action is taken it would lead to a condition known as acidosis. To provent this chemoreceptors in the walls of the carotid arteries (arteries that serve the brain) and the aorta detect this chemical change and increase the frequency of nervous impluses to the region of the medulla oblongata that increases heart rate. The medulla oblongata is the region of the brain which controls changes in heart rate. As a result the medulla oblongata increases the frequency of nervous impluses to the sino atrial node of the heart via the sympathetic nervous system which increases heart rate. Increased heart rate restults in removal of CO2 from the lungs increasing blood pH to its set point. This correction in the blood pH is detected by the chemoreceptors in the medualla oblongata which reduce the frequency of nerve impluses to the sino atrial node returning blood flow to normal which is an example of negative feedback.

    CO2 is removed from the body via the lungs. In plants CO2 is absorbed through tiny pores in the surface of the leaf called the stomata. In the body CO2 is carried around the blood by a heamoglobin molecule which takes it up when it unloads oxygen to the respiring cells. The CO2 produced by respiring cells is acidic and the low pH causes the tertiary structure of the heamoglobin molecule to alter and therefore it has a lower affinity for oxygen and it is released. CO2 molecules are taken up by the heamoglobin which has a higher affinity for CO2. When they reach the thin carpillaries in the alveoli of the lungs the concentration and hence acidicty of CO2 is low and the concentration of oxygen is high and so the heamoglobin molecules unload CO2 and take up oxygen once more. CO2 diffuses out of the lungs as the red blood cells carrying it pass through such thin carpilliaries that they are squashed up against the carpillary wall. This decreases the length of the diffusion pathway and so the difference in concentration causes the CO2 to diffuse out of into the lungs where it is exhaled. pH changes cause the tertiary structure of the globular protein as pH causes the disruption of disulphide/ionic/hydrogen bonds in the structure changing its shape. This is as acidic solution forms H+ ions which disrupt the charges in the bonds causing the denaturation/shape changes in the protein.

    CO2 can also effect organisms indirectly as it contributes to global warming and the greenhouse effect. It's a greenhouse gas that absorbs infared energy from solar radiation from the sun which has been reflected from the surface of the earth and releases it directing it back towards the earth surgace trapping heat close to the earths surface. This in turn causes ecosystems to change and could lead to extinction of species and a reduction in biodiversity. For example melting of the polar ice caps coulc lead to only a small number of organisms compared to the numbers that lived in this environment before to survive. This is because only organisms which possess the alleles which suit them to the new environment will survive creating a bottle kneck where most organisms will die. Those organisms best suited to the new environment such as those polar bears with the ability to swim long distances between ice sheets will outcompete less well adapted organisms and increase the probability they will successfully live long enough to mate and raise offspring passing their alleles onto the next generation. Changes in ecosystems could also affect humans as crop yields change both in size and the time of the harvest changes. Also it could mean some crops previously grown in one area can no longer grow there anymore affecting food sources. The increase in temperature could also causes diseases to move to areas of the world where they where never widespread before causing a reduction in biodiversity as few organisms might have the natural immunity or adaptations to survive in this new environement.
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    (Original post by Abby :))
    ^ To practice essays my teacher gave us a big booklet of all the past exam questions and their mark schemes. So im either reading over them, or actually writing them out.


    After revising this unit alot, im actually convinced its easier than Unit 4. (Apart from the essay aspect).
    hey do you have the essay booklet online? if so please could i have a copy
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    (Original post by hiyarearl)
    If I post up an essay I just had a go at could someone read it and maybe suggest what sort of marks I'd have gained/where there are errors or what I could add to it?

    How long should the essay be and in what detail should each topic with it be discussed? The essay below took me about 30 minutes or so to plan and write and took up 2 1/2 sides of A4

    QUESTION: CO2 may effect organisms directly or indirectly describe and explain these effects.

    ANSWER:

    CO2 is an important carbon based molecule required for photosynthesis in photosynythetic organisms. CO2 is involved in the assmiliation of organic molecules via the calvin cycle/light independant reaction which requires CO2 to reduce ribulose biphosphate to in turn produce glycerate-3-phosphate which is reduced by reduced NADP from the light dependant reaction produce triose phosphate to achieve this. Some triose phosphate is converted into organic molecules such as glucose and some is used to reform ribulose biphosphate so that the calvin cycle can continue.

    Glucose and other organic molecules produced in this process form the basis of organic plant cells and glucose itself acts as a energy source which can be used to produce ATP which is an energy carrier molecule required to provide energy for processes such as active transport which allow the plant to absorb mineral ions required for growth.

    CO2 can have a direct affect on human and other aerobic organisms. It is a produce of respiration and is transported via the blood from respiring cells to the lungs for removal. CO2 forms an acid when dissolved in solution and therefore in blood it is acidic. If the acidicy of blood increases unless corrective action is taken it would lead to a condition known as acidosis. To provent this chemoreceptors in the walls of the carotid arteries (arteries that serve the brain) and the aorta detect this chemical change and increase the frequency of nervous impluses to the region of the medulla oblongata that increases heart rate. The medulla oblongata is the region of the brain which controls changes in heart rate. As a result the medulla oblongata increases the frequency of nervous impluses to the sino atrial node of the heart via the sympathetic nervous system which increases heart rate. Increased heart rate restults in removal of CO2 from the lungs increasing blood pH to its set point. This correction in the blood pH is detected by the chemoreceptors in the medualla oblongata which reduce the frequency of nerve impluses to the sino atrial node returning blood flow to normal which is an example of negative feedback.

    CO2 is removed from the body via the lungs. In plants CO2 is absorbed through tiny pores in the surface of the leaf called the stomata. In the body CO2 is carried around the blood by a heamoglobin molecule which takes it up when it unloads oxygen to the respiring cells. The CO2 produced by respiring cells is acidic and the low pH causes the tertiary structure of the heamoglobin molecule to alter and therefore it has a lower affinity for oxygen and it is released. CO2 molecules are taken up by the heamoglobin which has a higher affinity for CO2. When they reach the thin carpillaries in the alveoli of the lungs the concentration and hence acidicty of CO2 is low and the concentration of oxygen is high and so the heamoglobin molecules unload CO2 and take up oxygen once more. CO2 diffuses out of the lungs as the red blood cells carrying it pass through such thin carpilliaries that they are squashed up against the carpillary wall. This decreases the length of the diffusion pathway and so the difference in concentration causes the CO2 to diffuse out of into the lungs where it is exhaled. pH changes cause the tertiary structure of the globular protein as pH causes the disruption of disulphide/ionic/hydrogen bonds in the structure changing its shape. This is as acidic solution forms H+ ions which disrupt the charges in the bonds causing the denaturation/shape changes in the protein.

    CO2 can also effect organisms indirectly as it contributes to global warming and the greenhouse effect. It's a greenhouse gas that absorbs infared energy from solar radiation from the sun which has been reflected from the surface of the earth and releases it directing it back towards the earth surgace trapping heat close to the earths surface. This in turn causes ecosystems to change and could lead to extinction of species and a reduction in biodiversity. For example melting of the polar ice caps coulc lead to only a small number of organisms compared to the numbers that lived in this environment before to survive. This is because only organisms which possess the alleles which suit them to the new environment will survive creating a bottle kneck where most organisms will die. Those organisms best suited to the new environment such as those polar bears with the ability to swim long distances between ice sheets will outcompete less well adapted organisms and increase the probability they will successfully live long enough to mate and raise offspring passing their alleles onto the next generation. Changes in ecosystems could also affect humans as crop yields change both in size and the time of the harvest changes. Also it could mean some crops previously grown in one area can no longer grow there anymore affecting food sources. The increase in temperature could also causes diseases to move to areas of the world where they where never widespread before causing a reduction in biodiversity as few organisms might have the natural immunity or adaptations to survive in this new environement.
    your essay is really good!! it makes me depressed about how bad my essays are! haha, ermm im not too sure what mark you would gues, but it seems like you have literally covered ATLEAST one thing from each unit so well done! im going to have to start revising more for this essay i havent even finished revising for unit 5 :afraid:
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    (Original post by (Online))
    Really?? :eek:
    That doesn't seem much. Oh, and don't worry, I never think that anymore, after one pitiful grade
    It doesn't seem like much to achieve but this exam will be the hardest one I'll do this summer
    (Original post by tehsponge)
    I'm interested to see it, and I will try to help
    There isn't much interesting about it it's rather weak in terms of scientific content and the highest grade I'll get at the moment is a D grade

    I'll post it up here between now and tomorrow and quote you
 
 
 
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