Chapter 7 Quizzes: Self Activities Chapter Cum. Videos   Movies    Words   Appendix    Summary   Art    Art 

Unit 2: The Cell Membrane Structure and Function Review
  1. The plasma membrane is a "fluid mosaic" made of with a mosaic of embedded in it, and exhibits permeability.
     
     
  2. Membranes contain amphipathic , containing both hydrophobic and hydrophilic regions, and form a , with embedded proteins.
     
     
  3. molecules and small molecules like O2 can pass through the membrane by diffusion; molecules and large molecules like glucose cannot.
     
     
  4. (passive transport) is the tendency for molecules to spread out evenly down their gradient.
     
     
  5. is the diffusion of across a membrane, and is affected by the concentration gradient of dissolved substances, or .
       
       
    • In environments where solute concentration is the as it is inside the cell, there is no net water movement.
       
       
    • In environments where solute concentration is than it is inside the cell, water tends to move the cell.
       
       
    • In environments where solute concentration is than it is inside the cell, water tends to move the cell.
       
       
    • Organisms without cell must have adaptations for to maintain water balance in hypotonic and hypertonic environments.
       
       
    • Plant cells fare best in environments.
     
     
  6. diffusion is the movement of molecules across the membrane facilitated by proteins, the concentration gradient.
       
       
    • proteins provide corridors that allow a specific molecule or ion to cross the membrane.
       
       
    • proteins undergo a change in shape that translocates the solute-binding site across the membrane.
     
     
  7. transport, such as sodium-potassium , is the movement of molecules their concentration gradient using energy, usually in the form of .
     
     
    Review.
     
     
  8. Large proteins cross the membrane by transport mechanisms.
     
     
  9. In . The cell takes in macromolecules by forming new from the plasma membrane via invagination.
     
     
  10. In , transport migrate to the plasma membrane, fuse with it, and release their contents.
bio1151b Home Jan 30, 2008 Print Print