Bio 256 1F

  1. Two molecular components of cell membrane
    • Lipids
    • proteins
  2. Two Types of membrane proteins
    • integral
    • peripheral
  3. Integral proteins
    • embedded in phospholipid bilayer
    • span entire thickness of membrane
    • exposed to both outside and inside of cell
  4. Peripheral proteins
    • not embedded
    • loosely attached to either external or internal cell wall
  5. Chemical concentration gradient
    move from high concentration to low
  6. electrochemical forces
    • seperation of charged ions across a membrane
    • anions attract cations
  7. Passive membrane transport
    • no energy required
    • high concentration to low (diffusion)
  8. Active Transport
    • Energy required
    • moved against concentration gradient
  9. Simple diffusion
    small or nonpolar molecules
  10. osmosis
    applies only to the movement of water
  11. Isotonic Solutions
    equal water concentration to inside cells
  12. Hypertonic solutions
    • less water (more solute)> draws water out of cell
    • cell shrinks (crenates)
  13. Hypotonic solutions
    • more water (less solute)> water moves into cell
    • cell bursts (lyses)
  14. In a resting muscle cell the membrane potential (E) is approximately____ mV and the cell is termed "___."
    -95mV, polarized
  15. All resting cells have similar proportions of ions across their plasma membranes. knowing this, predict which ion will be found to have a greater plasma concentration than normal if hemolysis occurs as a blood sample is collected.
  16. when a hormone stimulates a target cell, it binds receptors. This binding produces a second messenger inside the cell. The "first" messenger is________. 
  17. Facilitated Diffusion
    • large or polar molecules
    • requires specific integral protein that binds to molecule to be transported
  18. Bulk Filtration
    diffusion of both liquids and dissolved molecules through hydrostatic presssure
  19. Active transport
    • May involve ion pumps
    • bulk transporty
  20. Exocytosis
    Out of the cell
  21. endocytosis
    into the cell
  22. Phagocytosis
    nonspecific uptake of particles by formation of membrane extensions (pseodopia) that surround particles to be engulfed
  23. Pinocytosis
    nonspecific uptake of extracellular fluid
  24. receptor-mediated endocytosis
    engulfing of specific molecules bound to receptors on the surface of the plasma membrane
  25. Resting Potential
    • membrane is polarized- negative mB at rest
    • maintained by active transport ions
Card Set
Bio 256 1F
Cells and their environment