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    Okay - this might be stupid of me asking but:

    The process of gene therapy - is that genetic modification of plants and animals? Or am I getting confused between the two?
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    (Original post by hollywoodbudgie)
    Photoreceptors detect light hitting the retina... what detects a lack of light hitting the retina? :/
    Sorry stupid question I know...
    Nothing..

    When there is no light, the sodium channels in the rods/cones are already open. This produces an action potential and releases neurotransmitters.
    These neurotransmitters are INHIBITORY which stop a nerve impulse being sent to the brain.
    In dark this processes is going on continiously.. neurotransmitters are continiously being released to inhibit bipolar nerves.. or w/e


    GUYS!! I'm almost complete with my revision BUT I still need to learn the spirometer and respirometer... I know it has been asked already.. But does anyone have some good notes on these two practicals.. a step by step process is good enough..
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    Quick question guys...
    So I was doing past papers and there was a question about the fate of lactic acid. So I put - it can be converted into glycogen and stored in the liver and it can be converted back to pyruvate which is then used in the Link Reaction.
    But the mark scheme, A2 textbook and CGP book all say it's converted to pyruvate and then used in the Krebs Cycle...I know for a fact that it's Acetyl CoA that enters the Krebs Cycle after being converted from pyruvate in the Link Reaction...

    ...so what is all this about? Any ideas? :confused:
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    (Original post by skotch)
    .
    hey i just went through the possible questions u posted up. some really stumped me. do u mind helping me out with some of the questions from the second set?


    Compare and contrast the effect of adrenaline as a hormone with its action as a neurotransmitter.

    How can hydroxyl-dopamine selectively destroy the neurons that use noradrenaline as neurotransmitter

    What is the evidence that it is an imbalance of many different neurotransmitters and not just one neurotransmitter in particular (p9para5) that can cause stress related disorders

    can we describe pain as a polygenic inherited trait

    Suggest how oestrogen and progesterone might cause their antagonistic effects on the neurones

    Suggest how a chemical could block pain and counteract the effect of analgesics


    sorry to dump this whole lot on you! any help is appreciated
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    in the textbook it states Pfr is needed to stimulate flowering in long day plants but inhibits it in short day??? so wheres this lack of pfr inhibiting it coming from?
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    (Original post by koop)
    in the textbook it states Pfr is needed to stimulate flowering in long day plants but inhibits it in short day??? so wheres this lack of pfr inhibiting it coming from?

    In long day plants if Pfr stimulates flowering then ipso facto the lack of Pfr inhibits flowering..

    If you don't have the pigment which stimulates flowering then obviously it means the process of flowering is being inhibited due to the LACK of that pigment..
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    (Original post by Roxychick)
    Quick question guys...
    So I was doing past papers and there was a question about the fate of lactic acid. So I put - it can be converted into glycogen and stored in the liver and it can be converted back to pyruvate which is then used in the Link Reaction.
    But the mark scheme, A2 textbook and CGP book all say it's converted to pyruvate and then used in the Krebs Cycle...I know for a fact that it's Acetyl CoA that enters the Krebs Cycle after being converted from pyruvate in the Link Reaction...

    ...so what is all this about? Any ideas? :confused:
    Page 155 of Snab textbook..."Lactate is converted back into Pyruvate and oxidised directly to CO2 & H20 via the Krebs Cycle."
    Not sure entirely HOW that works, but I guess seen as it isn't explain you've just got to know that's what happens and that the excess O2 needed in this period is known as the "O2 debt" to cope.
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    (Original post by abcdemilyxx)
    soda lime/KOH absorbs the co2 so you're breathing in only o2 not co2 and you only need to measure the amount of o2.

    spirometer measures breathing rate and tidal volume and the amount of air in the chamber decreases over time. it can be used before during and after exercise.
    the respirometer has a manometer containing ink and as the insects in the tube respire, the ink will move upwards on the side that the insects are on due to pressure change which it controlled by a syringe on the other tube.
    Ah okay, but what exactly does the syringe do?
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    (Original post by rashahamed)
    the sodalime/ KOH is used so it can absorb the CO2, allowing the O2 concenration to be measured, if the Co2 is not removed the respirometers reading will not change because the same voume of co2 and o2 are produced during aerobic respiration.


    hope this helped!!
    o2 isn't produced during aerobic respiration..?
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    (Original post by _joshb_)
    Ah okay, but what exactly does the syringe do?
    Moves the liquid dye into position. That is all.
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    (Original post by _joshb_)
    Ah okay, but what exactly does the syringe do?
    the syringe allows you to change the pressure and set the manometer level back to normal.
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    (Original post by Roxychick)
    Quick question guys...
    So I was doing past papers and there was a question about the fate of lactic acid. So I put - it can be converted into glycogen and stored in the liver and it can be converted back to pyruvate which is then used in the Link Reaction.
    But the mark scheme, A2 textbook and CGP book all say it's converted to pyruvate and then used in the Krebs Cycle...I know for a fact that it's Acetyl CoA that enters the Krebs Cycle after being converted from pyruvate in the Link Reaction...

    ...so what is all this about? Any ideas? :confused:
    The link reaction is considered to be a part of the Krebs cycle. I read that somewhere.
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    Could someone please write the steps in gene therapy? I'm getting it all confused with GM =$

    Thanks in advance.
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    (Original post by Shining*)
    Could someone please write the steps in gene therapy? I'm getting it all confused with GM =$

    Thanks in advance.

    gene therapy is either germ line; changing sex cells, or somatic; changing body cells. either working dominant alleles or random bits of gene are entered into the DNA depending on if what you want to change is recessive or dominant.
    gm is cultivating microroganisms and inserting genes via restriction enzymes into plants/animals using vectors to change their DNA.
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    What they said..

    GM is in the topic 8.
    Gene therapy is probably synoptic info which may be useful for the article.
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    Ah! Thanks!
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    come on http://qchat.rizon.net/ and go on the 6BI05
    all the bio student are there
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    the O is the alphabet
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    (Original post by Doughboy)
    The link reaction is considered to be a part of the Krebs cycle. I read that somewhere.
    Link reaction and Krebs cycle are definitely different!

    The link reaction converts pyruvate to acetyl coenzyme A through the loss of CO2 and I think H+ as well, which is different to the Krebs cycle which involves the formation of an unstable 6C compound and its subsequent degradation forming NAD/FAD/substrate level ATP.
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    (Original post by terminatorsb)
    the O is the alphabet
    :lolwut:
 
 
 
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