biology help

Discussion in 'General Off-Topic Chat' started by cheatmaster5, Mar 9, 2010.

  1. cheatmaster5

    cheatmaster5 GBAtemp Regular

    Feb 19, 2009
    United States
    I need help with the following two questions.

    1) what limitations would be experienced in a cell if only diffusion were possible? Consider enzymatic reactions, the metabolic pathways., and other cell processes. How would they be affected.

    2) to investigate the process of photosynthesis, you have designed an experiment that uses small leaf discs that are infiltrated (filled) with a liquid by applying a vacuum. The result is the leaves sink since the liquid fills all the space inside the leaves. Exposure of the leaves to light eventually causes them to float. Explain what is happening as it relates to photosynthesis?

    Any help would be great
    Thanks in advance
  2. Blood Fetish

    Blood Fetish Quis custodiet ipsos custodes?

    Nov 3, 2002
    United States
    I like how your user name is cheatmaster.
  3. luke_c

    luke_c Big Boss

    Jun 16, 2008
    Land of England
    So GBAtemp now = Homework help club?
    Do your homework yourself like every other kid does.
  4. Danny600kill

    Danny600kill xD

    Aug 3, 2009
    United Kingdom
    I don't mind helping you with Biology seeing as my Biology GCSE is coming up soon and I need to ace it as I'm taking it in college. This is just from the top of my head and could be totally wrong or I may have interpreted the question wrong

    1. Something to do with certain things needed in a cell isn't possible through diffusion as they are moving against the concentration gradient which in turn means that the only possible way to gain or lose the specific things is to use active transport which requires energy and this is not possible according to the question. Its's the same with transporting water around the cell which would need the process of osmosis which again wouldn't be possible.

    2. I'm not exactly sure but I think it is just the simple fact that the liquid you added would be moved out of the leaf through either Osmosis ( If liquid is water ) or diffusion or even Active transport. This would then cause a space for air to move back into the spaces taken by the liquid in turn making the leaf rise to the surface

    I think they are right or parts of them are right anyway. Go Science [​IMG]


    Edit: xist is right I didn't take in the part relating to photosynthesis so it may just be as simple as the water is used in the process causing the space to fill with air again [​IMG]
  5. xist


    Jul 14, 2008
    I'd say you're right about the first, but off track on the second. The process of Photosynthesis involves water and carbon dioxide to produce Oxygen so i'd assume that the water in the leaf discs is being used in the reaction and thus is no longer present to weigh it down.
  6. Leo Cantus

    Leo Cantus So zeta slow!

    May 23, 2009
    Use Professor Google
  7. Dookieman

    Dookieman GBAtemp Regular

    May 1, 2008
    United States
    I think you are on track with the first question. I believe its simply if you rely only on diffusion, then ions that are need in opposition to the concentration gradient would not get to their proper locations. i.e. Transport proteins could not move large molecules through the lipid bi-layer.

    For the second question, the water was absorbed and used in the process of photosynthesis. Thus allowing it to float again.

    Glad I'm not the only science person on these forums.