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Recent content by alexkay

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    A level Biology: Post your doubts here!

    how was paper 41?
  2. A

    A level Biology: Post your doubts here!

    paper 4 tips, predictions?
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    Biology P51

    I said that as well for the control :)
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    Biology P51

    hey guys I'm really worried do you have to state the pH your using ?
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    A level Biology: Post your doubts here!

    Well I would assume you need to test the rate of reaction and control other variables that will affect that...so a high temp that denatures enzymes will affect the results adversely? Not sure...will I get a mark for stating 'control temp with a water bath'?
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    A level Biology: Post your doubts here!

    But wouldn't 60C denature the enzyme/protein? I never heard of that before! I used 35c but just said standardise temp using water bath?
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    A level Biology: Post your doubts here!

    I know how you feel :(
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    Biology P51

    I said that too, or something similar
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    Biology P51

    How was the stopwatch question?
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    Biology P51

    Yes but the first question effectively asked how to calculate rate of reaction (rate of substrate disappearing/ colour disappearing or sheet becoming transparent) to get the actual (optimum) concentration needed for the reaction.
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    A level Biology: Post your doubts here!

    Oh I also said the gelatin may be too thick n some replicates and so may take longer time
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    A level Biology: Post your doubts here!

    Mine too! I wrote more that 2 things just in case, I wrote judging the end point (when it is totally transparent) and I also said the stop watch may be broken/ not work properly and therefore inaccurate and also your personal judgement (using your eye) may be inaccurate and maybe something else...
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    A level Biology: Post your doubts here!

    The conclusions to the I said the as well but I also found the rate of reaction as the rate of substrate disappearing (colour disappearing) divided by time. I don't know if that is right. Then I said I looked up the optimum time needed to catalyse 100% of the protein and checked the conc on...
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    A level Biology: Post your doubts here!

    And how did you find the actual concentration using the graph?
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    A level Biology: Post your doubts here!

    what variables did you state in your method?
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