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Edexcel A2 Biology SNAB 6BI04 ~ 6BIO5 June 2016 Watch

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    (Original post by tayloryeah)
    i gurantee you this will get you full marks if you remember all of this x
    The spirometer trace
    -ventilation rate = tidal volume x breathing rate
    -Volume tube is calibrated
    -Time is calibrated
    -The tidal volume for each subject can be measured by the height from peak to trough
    -One breath = one breath
    -Breathing rate = number of peaks per minute
    -traces should be taken at rest
    -each subject should be the same gender and age
    -Repeat the experiment several times to gather a mean+ more reliable
    Thank you
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    guys how do i answer describe data questions theyre such a pain.


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    can someone tell me what exactly we need to know about GPP and NPP, rly rly stuggling with that part
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    (Original post by Algeriandz)
    can someone tell me what exactly we need to know about GPP and NPP, rly rly stuggling with that part
    if found this useful

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    guys what exactly are antiviral proteins and what do we need to know about them


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    (Original post by nahida1998)
    Question about the Unit 5 scientific article: in paragraph 25, it talks about the creation of a bacterial toggle switch: "collins announced the first artificial toggle switch in bacteria ; the scientists designed two promoters to interact and drive gene activity if prompted by one molecular signal and to stop when prompted again". Just wondering what all of that could mean??? Any ideas?
    Two promoters designed referring to two new transcription factors added.Two new genes added for the two new transcription factors. Some 'molecular signal' (maybe a reference to the function of steroid/peptide hormones to directly or indirectly affect transcription of a gene) turns on these genes to produce the transcription factors. Both transcription factors bind to a promoter region in DNA and causes some gene (likely another gene which has been added) to be transcribed and translated.

    That way they can 'turn a process on or off'.

    I think that's what it means. I don't know for sure whether I'm correctly interpreting what a promoter is.
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    (Original post by ranz)
    if found this useful

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    i literally found that page in the revision guide after i asked, lool thank u tho !
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    (Original post by Algeriandz)
    i literally found that page in the revision guide after i asked, lool thank u tho !
    no prob haha!


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    What's the difference between a CD4 on a macrophage and an MSH????
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    (Original post by drjay24)
    What's the difference between a CD4 on a macrophage and an MSH????
    msh?


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    oops I meant MHC haha
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    (Original post by drjay24)
    oops I meant MHC haha
    mhc?
    lol im terrifiedd of bio exam !
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    (Original post by ranz)
    mhc?
    lol im terrifiedd of bio exam !
    I get what you mean, and apparently they mark the A2 coursework quite harshly too ((

    And I looked up MHC, it's when an antigen binds to the the mhc (on the membrane) forming an APC. That's all we have to know
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    (Original post by drjay24)
    What's the difference between a CD4 on a macrophage and an MSH????
    CD4 is the receptor where the antigen binds, MHC is inside the cell and presents the antigen on the surface membrane once it's been broken up into fragments. So CD4 = receptor for antigen to bind, MHC = presenting already broken up antigen
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    Forgot to ask!!!! How did everyone do on the coursework?! How many pages did everyone do?!
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    Is it just me or is the June 2014 reserve paper quite hard
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    (Original post by ranz)
    guys what exactly are antiviral proteins and what do we need to know about them


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    Antiviral proteins are part of the response lead by interferon,

    Interferon inhibits viral infections
    The protein is secreted by viral infected cells.
    It stimulates cells to produce antiviral proteins to inhibit viral proteins
    They prevent viruses attaching to other host cells, to prevent further infection
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    (Original post by Algeriandz)
    can someone tell me what exactly we need to know about GPP and NPP, rly rly stuggling with that part
    NPP= the rate at which energy is transferred into organic matter to make up new biomass of a plant (energy stored)

    GPP= the rate at which energy is incorporated into organic matter by a plant ( energy used)

    GPP> NPP
    because energy loss mainly comes from respiration in the form of heat.
    NPP= GPP-R
    Other sources of energy loss: inedibility of a plant ,urine and faeces, movement and reproduction.
    In relation to a plant: photosynthetic inefficiency may include, the wrong wavelength thus the light is reflection, excess light and the light may not be hitting the chlorophyll molecules
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    Can one gene code for many protein? Is it because there is a large variety of ways exons can be arranged therefore alters the primary structure of a protein?
    Could someone explain this to me? Am I correct?
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    (Original post by kosvengali)
    Can one gene code for many protein? Is it because there is a large variety of ways exons can be arranged therefore alters the primary structure of a protein?
    Could someone explain this to me? Am I correct?
    yes, you're correct
    exons = contain genetic code
    introns = do not contain genetic code
    During post transcriptional changes, Introns are spliced out of the mRNA strand catalysed by splisosome. Exons are recombined in many different ways giving rise to to different combinations of mRNA, therefore many proteins can be produced from one gene as the mRNA acts as the template for the tRNA molecules which carry the specific amino acid to compliment the codons on the mRNA strand (using anticodons). This sequence determines the sequence of amino acids in the primary structure which determines what and where bonds form and as a result how the protein folds (between R groups) including; hydrogen bonding, disulphide bridges and ionic bonding!
 
 
 
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