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Biology Question: HELP PLEASE!

  1. Sep 27, 2008 #1
    Proteins associated with the plasma membrane can be classified as either integral membrane proteins or peripheral membrane proteins. For the following types of proteins, please specify whether they would be integral or peripheral.
    Glucose transporter
    Sodium-potassium pump
    Ion channel

    -I think that peripheral membranes are only on one side of the membrane whereas integral proteins are on both sides of the membrane. Therefore, I thought that glucose transporter was integral, sodium potassium was integral, and ion channel was peripheral. What am I doing wrong???

    Transport of large or hydrophilic molecules across the plasma membrane can occur via facilitated diffusion or via active transport. For the following types of proteins, please indicated which type of transport is involved.

    Ion channel
    Glucose transporter GLUT-1
    Sodium-potassium pump

    Active transport is when molecules can cross against the concentration gradient whereas faclitated diffusion can't go across the concentration gradient. So this is what I did: for ion channel, I said faclitated diffusion, glucose transporter is active transport, and sodium potassium pump is active transport. Where am I going wrong?

    Any help would be appreciated! Thanks.
  2. jcsd
  3. Sep 28, 2008 #2


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