Hey there! Sign in to join this conversationNew here? Join for free
x Turn on thread page Beta
    Offline

    0
    ReputationRep:
    (Original post by lagoom)
    an action potential in a region causes an action potential in an adjacent reason, this is beacuse when a certain region is being depolarised, sodium ions diffuse side ways to the adjacent region, the presence of the sodium ions causes the adjacent region to become depolarised, gated sodium channels open, as more and more sodium ions diffuse into the axon more and more channels open- positive feedback
    Thank you!
    Offline

    0
    ReputationRep:
    (Original post by Bright)
    Yikes! :eek: Good luck, hope you get it! :] that's like me and chemistry.. I only know I got an A for unit 1 and courseworks, hope the same in exams

    and I need a 126 UMS to get an A, so a B in this I think. I'm assuming my coursework was utterly crap so the higher the better :l
    Ah thank you! Thats really good, i always found chemistry impossible lol. Good luck with bio, im sure you'll be able to get at least a B


    This was posted from The Student Room's iPhone/iPad
    Offline

    0
    ReputationRep:
    (Original post by ZTSR)
    Electron transport chain.

    How is high concentration of H+ ions maintained in the inter membrane space ?

    Coenzymes - either NADH+ or FADH+ - break down into protons and electrons
    The electrons travel along the ETC, through a series of redox reactions and release energy
    This energy is used to move H+ protons from the matrix to the intermemberane space
    They move down their concentration gradient
    Offline

    2
    ReputationRep:
    (Original post by lagoom)
    depolarisation in a region causes depolarisation in an adjacent reason, this is beacuse when a certain region is being depolarised, sodium ions diffuse side ways to the adjacent region, the presence of the sodium ions causes the adjacent region to become depolarised, gated sodium channels open, as more and more sodium ions diffuse into the axon more and more channels open- positive feedback
    I remember you from unit 4 and 2 loool.. nice to see you again! (don't think you'll remember me)
    Offline

    0
    ReputationRep:
    (Original post by nadzzdan)
    Guys does anyone understand JAN 12 paper question 1aiii)?
    Yeah, the light come in from the top, the bottom of the picture is the back of the eye, the light then bounces back up to the optic nerve which is at the top of the picture, to send impulses on the brain
    ^^sorry for the rubbish explanation, it's also in the textbook page 219
    Offline

    0
    ReputationRep:
    (Original post by charlotte.yellow)
    Yeah, the light come in from the top, the bottom of the picture is the back of the eye, the light then bounces back up to the optic nerve which is at the top of the picture, to send impulses on the brain
    ^^sorry for the rubbish explanation, it's also in the textbook page 219
    oh righty thanks for that
    Offline

    0
    ReputationRep:
    (Original post by M Kh)
    Guys here are the unit 5 topic 8 notes: http://www.mediafire.com/view/?0axz4vqmxxyq1at

    All credits to the original uploader. All rights reserved.
    hey, thanks for uploading your notes!
    in your notes it says pr gets converted to pfr at night, i thought pfr gets converted to pr at night as the pr form is more energetically stable, even though pfr is the biologically active one, chemicals tend to revert to their energetically stable form
    Offline

    0
    ReputationRep:
    (Original post by charlypennington)
    can someone please give me a bullet point outline of the sliding filament theory?
    - Stimulus reaches muscle and calcium ions diffuse in from sarcoplasmic reticulum
    - calcium ions bind to troponin protein on the actin filament
    - This causes the tropomyosin to detatch from the troponin
    - The actin-myosin binding site is now exposed
    - Myosin heads then bind to the binding site
    - They break down an ATP molecule - releasing energy
    - This causes a power stroke and the head poivits
    - The actin fillament is pulled in
    - ATPase then synthesises ADP + Pi to make ATP
    - This attachtes to myosin head and head is released from binding site and the the head returns to original position
    - When no stimulus, no calcium ions are released and the muscle is relaxed
    Offline

    0
    ReputationRep:
    (Original post by lagoom)
    hey, thanks for uploading your notes!
    in your notes it says pr gets converted to pfr at night, i thought pfr gets converted to pr at night as the pr form is more energetically stable, even though pfr is the biologically active one, chemicals tend to revert to their energetically stable form
    Pfr is converted into Pr in the dark
    Pr is converted into Pfr in the light

    You are right
    Offline

    0
    ReputationRep:
    GUYS - respirometer core practical NOT likely to come up.
    Habituation is MOST LIKELY
    Learn spirometer too
    Offline

    2
    ReputationRep:
    (Original post by hannah_27)
    .
    Thanks for the notes!
    Have you got topic 7 too?
    Offline

    0
    ReputationRep:
    (Original post by hannah_27)
    GUYS - respirometer core practical NOT likely to come up.
    Habituation is MOST LIKELY
    Learn spirometer too
    habituation most likely ??! HOW ?!
    it came this year in unit 6 !!
    Offline

    2
    ReputationRep:
    (Original post by iesians)
    habituation most likely ??! HOW ?!
    it came this year in unit 6 !!
    What on Earth is unit 6?! o_O
    Offline

    0
    ReputationRep:
    (Original post by Bright)
    What on Earth is unit 6?! o_O
    OH SORRY ! you guys are locals ! we have an international asesment which alternative to practical for you guys , so habituation came in that paper for us ....
    Offline

    0
    ReputationRep:
    (Original post by Bright)
    What on Earth is unit 6?! o_O
    I second this.
    What the heck is unit 6?!
    Offline

    0
    ReputationRep:
    what is positive feedback mechanism ? why is it important in some situations ? (2 marks)
    Offline

    0
    ReputationRep:
    (Original post by iesians)
    OH SORRY ! you guys are locals ! we have an international asesment which alternative to practical for you guys , so habituation came in that paper for us ....
    ooooo - so that basically still means that it wont come up!
    sick
    learn spirometer
    Offline

    0
    ReputationRep:
    Have you got topic 7 too?
    The brother posted the topic 7 notes on here yesterday, few pages back.
    Offline

    0
    ReputationRep:
    (Original post by hannah_27)
    ooooo - so that basically still means that it wont come up!
    sick
    learn spirometer
    ikr !! respirometer came in jan
    habituation came in unit 6
    so that just leaves spirometer !
    i wonder if i left any other practical in unit 5 .......:rolleyes:
    Offline

    1
    ReputationRep:
    (Original post by iesians)
    what is positive feedback mechanism ? why is it important in some situations ? (2 marks)
    When a change encourages further changes of the same sort to occur, i.e. when the sodium channels change shape in the action potential, it starts off with a few channels opening, and then lods of channels open
 
 
 
Reply
Submit reply
Turn on thread page Beta
Updated: April 30, 2013
Poll
Do you agree with the proposed ban on plastic straws and cotton buds?

The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

Write a reply...
Reply
Hide
Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.