Biology 172 Lecture 7

  1. Proteins can be amphipathic. Amphipathic proteins can...
    integrate into lipid bilayers.
  2. molecules vary in their ability to cross membranes based on their ...
    • size
    • polarity
    • charge
  3. Simple Diffusion
    • movement of molecules across a membrane down a concentration gradient
    • no energy required
    • not saturable (no protein involved)
    • Movement from higher free energy to lower free energy
  4. Cell membranes are _______ to small _______ (nonpolar) molecules
    • permeable
    • hydrophobic
  5. Molecules move randomly, but ___ movement is ______ ______ ______
    • net
    • down concentration gradient
  6. Facilitated Diffusion
    • movement across a membrane down a concentration gradient with the aid of transport proteins
    • no energy required
    • is saturable (occurs through a protein)
    • Movement from higher free energy to lower free energy
  7. An electrochemical gradient is a ...
    • Combined Concentration
    • and Electrical Gradient
  8. What determines movement?
    Concentration and charge
  9. Facilitated Diffusion, proteins
    • Polar solutes cannot cross the lipid bilayer alone
    • They are aided by transport proteins
    • Transport proteins are specific for their cargo
  10. Water moves by osmosis
    a special case of facilitated diffusion
  11. aquaporins
    • channel proteins
    • water moves across membranes through water channels
  12. Osmosis
    water will move down a concentration gradient (from low solute to high solute concentration) across a biological membrane
  13. Active Transport
    • movement of molecules across a membrane against a concentration gradient with the aid of transport proteins
    • requires energy
    • is saturable
    • going from lower concentration to a higher
  14. Why is ATP required
    need energy, and you get it from hydrolizing ATP
  15. Transport proteins can move more than one type of molecule in the same or opposite direction
    • uniport: one molecule same direction
    • symport: 2 molecules same direction
    • antiport: 2 molecules opposite directions
  16. The sodium-potassium pump
    an example of active transport is ..
    an antiport
  17. Carbohydrates
    • basic formula CH2O
    • Carbonyl group, Hydrozyl groups
    • include sugars and polymers
    • Monosaccharides (simple sugars)
    • vary in carbon number, position of carbonyl group, arrangement of atoms
    • name of most sugars end in ose
  18. Carbohydrates from ____ in aqueous solutions
    ring structures
  19. Disaccharides
    two monosaccharides joined by a glycosidic bond
  20. Polysaccharides
    many monosaccharides joined by glycosidic bonds
  21. Polysaccharides = macromolecules
    Fuel Storage?
    • Fuel storage:
    • Starch (plants)
    • Glycogen (animals)
    • Structural:
    • Cellulose (plant cell wall)
    • Chitin (arthropod exoskeleton, fungal cell wall)
  22. Nucleic Acids
    • composed of nucleotides (differ in RNA and DNA)
    • Joined by phosphodiester bonds: phosphate group of 5'C of sugar linked to hydroxyl on 3'C of next sugar chain
    • Sugar-phosphate backbone
Card Set
Biology 172 Lecture 7
Biology 172 Lecture 7 exam review