Chapter 7-Packet

  1. Describe how phospholipids with unsaturated hydrocarbon chains affect membrane fluidity?
    It remains fluid to a lower temp. if rich in phospholipids with unsaturated hydrocarbon chains, because the double bonds prevent it from packing closely together.
  2. __: resisting changes in membrane fluidity that can be caused by temp. change
    temperature buffer
  3. What are the types of membrane protiens? (6)
    • Transport
    • Enzymatic
    • Signal Transduction
    • Cell-Cell recognition
    • Intercellular joining
    • Attachment to cytoskeleton and ECM
  4. __:
    channel: a protien that spans the membrane may provide a hydrophilic channel across the membrane that's selective for a particular solute;
    carrier: shuttles substances from one side to the other by changing shape- hydrolyze ATP as energy source
    - facilitative diffusion is a part of this
    transport protein
  5. __: a protein built into membranes may be an enzyme with its active site exposed to substances in the adjacent solution. In some cases, several enzymes in a membrane are organized as a team that carries out sequential steps of a metabolic pathway.
    enzymatic proteins
  6. __: membrane protein may have binding site with specific shape that fits shape of chemical messenger- like a hormone. External messenger may cause a shape change in the protein that relays teh message to the inside of the cell, usually by binding to the cytoplasmic protein
    signal transduction
  7. __: some glyco-proteins serve as identification tags that are specifically recognized by membrane proteiins of other cells
    cell-cell recognition
  8. __: membrane proteins of adjacent cells that may hook together in various kinds of junctions (gap/ tight)
    intercellular joining
  9. __: microfilaments and other elements of cytoskeleton may be non-covalently bound to membrane proteins, a function that helps maintain cell shape and stabilizes the location of certain membrane protiens. Proteins that can bind to ECM molecules can coordinate extra and intracellular changes
    Attachment to cytoskeleton and ECM
  10. Membrane carbohydrates are important in cell-cell recognition. What are two examples of this?
    glycoproteins and glycolipids.
  11. Cells recognize each other by ___ to certain molecules.
  12. Are transport proteins specific? Why or why not?
    • Yes
    • because it is specific for the substance it translocates, allowing only a certain substance to cross the membrane.
  13. _____received the Nobel Prize in 2002 for the discovery of aquaporins
    Peter Agre
  14. __: channel proteins in the plasma membrane of a plant, animal, or microorganism cell that specifically facilitates osmosis.
  15. __: spontaneious movement of substance down its concentration gradient, from a more concentrated to a less concentrated region
  16. __: region along which the density of a chemical substance increases or decreases
    concentration gradient
  17. Plant cells become ___ if it has a greater solute concentration than its surroundings.
  18. Plant cells become __ if there is no net entry or exit of water.
  19. phenomenon in walled cells in which cytoplasm shrivels and the plasma membrane pulls away from the cell wall (when cell loses water to hypertonic environment)
  20. ___: spontaneous passage of molecules or ions across a biological memrane with the assistance of specific transmembrane transport proteins.
    facilitated diffusion
  21. Is facilitated diffusion active or passive transport? Support your response.
    passive because its helping a substance go down its concentration gradient, not against its concentration gradient.
  22. What type of transport proteins are involved in active transport?
    carrier proteins
  23. What is the role of ATP in active transport?
    • supplies the energy for active transport
    • transfers terminal phosphate group directly to transport protein
    • transport protein changes shape
    • ions move out/into cell
  24. __: coupling of the "downhill" diffusion of one substance to the "uphill" transport of another against its own concentration gradient.
  25. __: a molecule that binds specifically to another molecule, usuall a larger one.
  26. Review this image
    Image Upload 2
  27. Review this concept.
    Image Upload 4
  28. this measurement has a minimum value of 0 (when the solution is open to the environment); it increases as pressure increases
    pressure potential
  29. the diffusion of small solutes through a selectively permeable membrane
  30. this happens when a cell swells until pressure bursts it, resulting in cell death
  31. this measurement has a maximum value of 0; it decreases as the concentration of a solute increases
    solute potential
  32. the region along which the density of a substance decreases
    concentration gradient
  33. the function of membrane proteins that allow proteins to have binding sites with specific shapes that fit chemical messengers; external messengers may cause a shape change in protein that relays a message to the inside of the cell, usually by binding to a cytoplasmic protein
    signal transduction
  34. the proteins of a membrane that span the entire membrane
    transmembrane proteins
  35. the proteins of a membrane that penetrate the hydrophobic core of the lipid bilayer; hydrophobic regions consist of nonpolar amino acids, while hydrophilic regions are exposed to aqueous solution on either side of membrane
    integral proteins
  36. n a membrane protein, specifically a transport protein, that holds onto molecules and changes their shapes in a way that shuttles them across the membrane
    carrier proteins
  37. the function of membrane proteins that allows travel through a hydrophilic channel, or by transport proteins, which shuttle molecules across the membrane by changing shape with the help of hydrolyzing ATP
  38. this happens when water moves, but the amount within the cell is constant; no pressure builds
  39. the proteins of a membrane that are not embedded in the lipid bilayer; they are appendages loosely bound to the surface of the membrane, often exposed to parts of the integral proteins; attached by cytoskeleton on cytoplasmic side, and by fibers of ECM on extracellular side
    peripheral proteins
  40. any molecule that bonds specifically to a receptor site of another molecule
  41. the ability of a solution to cause a cell to gain or lose water; depends partly on concentration of nonpenetrating solutes relative to inside of cell
  42. the control of water balance
  43. when a substance diffuses from an area of lower concentration to an area of higher concentration, it is moving ______ its concentration gradient
  44. this happens when a cell shrinks and shrivels; can result in cell death if severe
  45. this states that water will always move from an area with high water potential to an area with low water potential.
    water potential
Card Set
Chapter 7-Packet