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    Hi Guys,
    The exam is on the Wednesday, so thought there could be a thread to see how everyone is feeling about it and we can post questions or queriers here.
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    topic 5 and 6 are the most difficult in my opinion. I think plant transport will be a large topic on the upcoming F211 exam as it hardly appeared in May 2013.
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    Fortunately I started to revise ages back and am quite confident on F211 however I have a habit for cocking up by making the most stupidest of mistakes xD
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    I think there'll be lots on plant transport too, the worst topic
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    Does anyone know if we have to know the mechanism by which the stomata open and close? It is in the revision guide but it isn't on the specification.
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    Do you reckon the heart will come up?!


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    (Original post by R-123)
    Do you reckon the heart will come up?!


    Posted from TSR Mobile
    Yes i think it's very likely the heart will come up, considering it was not in the exam last year (i took it last year) and also because both edexcel and ocr missed it off the spec last year, i think it is highly likely it will be on both exam papers this year
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    (Original post by StartingTheParty)
    Does anyone know if we have to know the mechanism by which the stomata open and close? It is in the revision guide but it isn't on the specification.
    I think it depends on what grade you're aiming for. If you're aiming for a B or above then learn it! It's really simple, and all it is, is osmosis in simple terms
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    Ffs
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    Does anyone have the june 2013 past paper?
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    The cardiac cycle will definitely come up, and probably translocation. Anyone else think cell signalling/exocytosis will come up?
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    (Original post by Harmanosa)
    The cardiac cycle will definitely come up, and probably translocation. Anyone else think cell signalling/exocytosis will come up?
    Agree with all of this! This is my main priority of revision material to cover tonight.
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    I have done zero revision the whole year, and I am not really scared bc I'm dropping it anyway. But I just don't want to embarrass myself getting less than a B when that's my minimum grade. And cardiac cycle and translocation are the things that always kill me in past papers. I'm gonna have a fun night LOL
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    Plant transport and the cardiac cycle...joy of joys. I have a feeling we'll end up with some horrendous cells questions, as well, because they were quite nice last year...
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    I think the Bohr effect and spirometer will be on it too...
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    Could someone please explain the Bohr effect to me?
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    (Original post by lidiax)
    Could someone please explain the Bohr effect to me?
    It basically states that in the presence of carbon dioxide, the oxygen affinity for dissociation of respiratory pigments, such as hemoglobin, decreases; because of the Bohr effect, an increase in blood carbon dioxide level or a decrease in pH causes hemoglobin to bind to oxygen with less affinity.
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    (Original post by BioNazma)
    It basically states that in the presence of carbon dioxide, the oxygen affinity for dissociation of respiratory pigments, such as hemoglobin, decreases; because of the Bohr effect, an increase in blood carbon dioxide level or a decrease in pH causes hemoglobin to bind to oxygen with less affinity.
    So when carbon dioxide is present, haemoglobin has a lower affinity for oxygen as it dissociates with it more readily. And that's basically just what the Bohr effect is? (and the curve is to the right of the graph?)
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    (Original post by lidiax)
    So when carbon dioxide is present, haemoglobin has a lower affinity for oxygen as it dissociates with it more readily. And that's basically just what the Bohr effect is? (and the curve is to the right of the graph?)
    essentially:

    Haemoglobin gives up oxygen more readily at higher partial pressures of carbon dioxide. This means more oxygen is delivered to cells during activity (the respiring cells releases CO2 which raises the partial pressure of carbon dioxide, increasing the rate of oxygen unloading. Most of the CO2 from respiring tissues diffuses into red blood cells and is converted into carbonic acid by the enzyme carbonic anhydrase. The rest (about 10%) of CO2 binds directly to haemoglobin and is carried in the lungs. The carbonic acid splits up to give hydrogen ions and hydrogencarbonate ions. This increase in hydrogen ions causes oxyhaemoglobin to unload its oxygen so that haemoglobin can take up the H+ ions. This forms a compounds called haemoglobinic acid. This process also stops the H+ from increases the cell's acidity. The hydrogencarbonate ions diffuse out of the red blood cells and are transported in the blood plasma. When the blood reaches the lungs, the low partial pressure of carbon dioxide causes the hydrogencarbonate ions and H+ ions to recombine into CO2. The CO2 then diffuses into the alveoli and is breathed out.
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    (Original post by ThatWasHard!)
    essentially:

    Haemoglobin gives up oxygen more readily at higher partial pressures of carbon dioxide. This means more oxygen is delivered to cells during activity (the respiring cells releases CO2 which raises the partial pressure of carbon dioxide, increasing the rate of oxygen unloading. Most of the CO2 from respiring tissues diffuses into red blood cells and is converted into carbonic acid by the enzyme carbonic anhydrase. The rest (about 10%) of CO2 binds directly to haemoglobin and is carried in the lungs. The carbonic acid splits up to give hydrogen ions and hydrogencarbonate ions. This increase in hydrogen ions causes oxyhaemoglobin to unload its oxygen so that haemoglobin can take up the H+ ions. This forms a compounds called haemoglobinic acid. This process also stops the H+ from increases the cell's acidity. The hydrogencarbonate ions diffuse out of the red blood cells and are transported in the blood plasma. When the blood reaches the lungs, the low partial pressure of carbon dioxide causes the hydrogencarbonate ions and H+ ions to recombine into CO2. The CO2 then diffuses into the alveoli and is breathed out.
    ah ok thank you!
 
 
 
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