physiology 6

  1. Integral proteins
    Extends into or through the lipid bilayer and are firmly embedded it it. ( most are transmembrane proteins)
  2. Hydrophilic
    polar portion water loving
  3. hydrophobic
    • non polar portion
    • water fearing
    • 2 long fatty acid chains
  4. Transmembrane proteins
    • span the entire lipid bilayer and protrude into the cytosol
    • includes channels that allow ions to cross the membrane
  5. peripheral protein
    not as firmly embedded, loosely bount to the membrane by associations
  6. glycoprotein
    • proteins with an attacthed carbohydrate group at the end of the protein that protrudes into the extracellular fluid
    • enables a cell to recognize other cells of same kind or to recognize and respond to dangerous foreign cells
    • located mainly on the extracellular surface
  7. Antigen
    Any material that causes an immune response
  8. Fluid mosaic model
    • called so because of the presence of proteins that are dispersed in the bilayer
    • consists of phospholipids, cholesterol, proteins and carbs
  9. what parts of the membrane are hydrophilic vs parts that are hydrophobic
    • the fatty acid "tails" are hydrophobic/non polar
    • the "head" is hydrophilic/ polar
  10. Peripheral proteins
    loosely bound to the membrane by associations with integral membrane proteins or phospholipids
  11. Integral Proteins
    extend into or through the lipid bilayer and are firmly embedded in it
  12. Transmembranal Proteins
    • Spans the entire lipid bilayer and protrudes into the cytosol
    • includes channels that allow ions to cross the membrane
  13. Cholesterol
    interferes with hydrophobic interactions between phospholipid tails, which may cause crystallization of the bilayer and may decrease fluiditity
  14. Functions of membrane proteins
    • form ion channels
    • act as transporters
    • some are enzymes
  15. Tight junction
    • serves as a barrier
    • blood/brain
    • stomach
  16. Desmosome ( Adherence) Junction
    • Specialized in cell to cell adhesion
    • provides strength so cells dont tear apart
    • heart, uterus, skin
  17. Gap junction
    • Communication junction allows cells to communicate very quickly
    • neurons
  18. Active transport
    transportation of molecules across a membrane that requires energy
  19. Permeable
    able to move across a membrane with ease
  20. Concentration gradient
    unequal distribution of ions
  21. diffusion
    movement of material from high concentration to low concentration
  22. Osmosis
    Diffusion of water across a membrane
  23. Membrane channel
    pathway that allows for movement of material from one end to another
  24. Voltage
    unequal charge distribution across the membrane
  25. Membrane potential
    a difference in electrical potential or voltage that appears across the membranes of most cells
  26. Electrochemical gradient
    the sum of the electrical and chemical gradients acting on an ion or charged molecule
  27. Facilitated diffusion
    the passive movement of molecules across a membrane by way of a transport protein
  28. Functions of the cell membrane
    • separates the cell from the extracellular fluid
    • contains the organelles of the cell
    • allows for some permeability
    • movement of ions in or out
  29. factors that determine permeablilty of a material
    • size of channel
    • charge of interior portion of channel
    • shape of diffusing molecule
    • temperature
    • membrane thickness
    • lipid solubility
  30. Active movement
    • requires energy
    • moves against concentration gradient

    passive moves with gradient
  31. Diffusion, Osmosis
    Passive transport
  32. sodium / potassium pump
    active transport
  33. sodium potassium pump
    • the pump works to reestablish sodium concentrations outside the cell and potassium concentrations inside the cell after an action potential.
    • It uses energy to pump 3 na out and to put 2 k in.
  34. membrane channel regulation
  35. membrane channel structure
  36. Endocytosis
    Molecules in the extracellular fluid enter the cell through the formation of vesicles called endosomes( from the plasma membrane)
  37. Phagocytosis
    • cell eating
    • cell uses movements of its membrane to form an enclosed phagosome in the cytoplasm
    • common in white blood cells for removing foreign particles and bacterial
  38. Pinocytosis
    • membrane indents and pinch together to enclose the particle
    • cell drinking
    • non specific process and the contents of the vesicle is extracellular fluid containing dissolved solutes
  39. Exocytosis
    vesicle inside the cell fuses with the membrane and releases its contents into the extracellular fluid
Card Set
physiology 6
membranes and function