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Cell membrane-please help me -

  1. Sep 14, 2005 #1
    cell membrane---please help me...---

    :confused: What kind of molecules make up the majority of the cell's membrane? :confused:

    Can anyone help me?
     
  2. jcsd
  3. Sep 14, 2005 #2
    can anyone help me?
     
  4. Sep 14, 2005 #3

    iansmith

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  5. Sep 14, 2005 #4

    JamesU

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    The majority of the membrane is made up of phospholipids
     
  6. Sep 14, 2005 #5
    PHospholipid bilayer is whre the most mass of the cell membrane is. Within the phospholipid bilayer there are embeded protiens (usually for trafficing/policing/regulating/assisting things that go in and out of the cell). There are also these things called Glycoproteins and glycolipids (carbohydrates i think?!) that are like little fingers of hairs that are used to identify other tissue and decide weather it is foreign or not. It is a glycoprotein if the carb is attached to the proteins embedded in the bilayer, and the carb is a glycolipid if it is attached to one of the phospholipids in the bilayer. Glycoproteins and Glycolopids also sometimes help with the transfer of large things into the cell.

    the phospholipid bilayer is a bunch of these tiny cells with tails that all line up like a palisade fence, there are two layers of themand each layer points its head outwards and sticks its tail part inwards, so between the bilayer u have a bunch of phospholipid tails, and the heads are facing to the outside and inside of the cell




    example phospholipid

    ~~~~~0





    I hope I didnt leave anything out
     
  7. Sep 14, 2005 #6
    Maybe a strange question

    but is there ANYTHING in-between the phospholipid bilayer itself? as in between the space where the two heads are... where all the tails are crammed together and the proteins are integrated into the cell membrane. cholestrol? or is all that space inbetween the bilayer taken up by the tails and proteins?
     
  8. Sep 14, 2005 #7

    JamesU

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    The tails are hydrocarbons and fatty acids. That little space is called 'intercellular space' and the only things that might go in there are cholesterols and transmembrane proteins.
     
  9. Sep 14, 2005 #8

    Moonbear

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    Keep in mind that when you see those diagrams of balls and sticks, those represent the carbon backbone of fairly large molecules that themselves take up space. How much actual space is between the molecules would be determined by the chemical interactions and how tight those molecules can be packed. Transmembrane proteins can span across the entire bilayer, and other membrane-bound proteins or other molecules will have their more hydrophobic domains stuck inside the bilayer.

    The intercellular space is the space between cells, not the space inside the membrane.
     
  10. Sep 14, 2005 #9

    JamesU

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    whoops. got a lot more to learn. :redface:
     
  11. Sep 15, 2005 #10

    Moonbear

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    Hey, no problem, that's what we're here for. :smile: Better you found out here that you misunderstood something than find out after you get an exam grade back. :wink:
     
  12. Sep 15, 2005 #11

    JamesU

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    since you're helping me with exam grades...how about I sneak out a copy of our next test and you 'help'with it :biggrin:
     
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