Quizlet AP Bio Chapter 7 Vocab

Print Options

This box will be automatically hidden when printing. Return to Set Page


  1. active transport: to pump a molecule across a membrane agaist its gradient requires work; the cell must expend energy
  2. amphipathic molecule: a phospholipid is an ________ _________; it has both a hydrophilic and a hydrophobic region
  3. aquaporins: the passage of water molecules through the membrane in certain cells is greatly facilitated by channel proteins called ___________
  4. carrier proteins: some transport proteins, called _____ ____, function by having a hydrophilic channel that certain molecules or atomic ions can use as a tunnel through the membrane
  5. cell-to-cell recognition: _____-__-____ ________ is a cell's ability to distinguish one type of neieghboring cell from another
  6. contrasport: a single ATP-powered pump that transports a specific solute can indirectly drive the active transport of several other solutes in a mechanism called _________
  7. diffusion: _______ is the tendency for molecules of any substance to spread out evenly into the available space
  8. electrogenic pump: a transport protein that generates voltage across a membrane is called a _______ ________
  9. endocytosis: the cell takes in macromolecules and particulate matter by forming new vesicles from the plasma membrane
  10. exocytosis: the cell secretes macromolecules by the fusion of vesicles with the plasma membrane
  11. facilitated diffusion: many polar molecules and ions impeded by the lipid bilayer of a membrane diffuse passively with the help of transport proteins that span the membrane
  12. flaccid: if a plant's cells and their surroundings are isotonic, there is no net tendency for water to enter, and the cells become _______
  13. fluid mosaic model: the membrane is a fluid structure with a "mosaic of various proteins embedded in or attached to a double layer (bilayer) of phospholipids (what kind of model is this?)
  14. freeze fracture: a method of preparing cells for electron microscopy is called _____ ______, which splits a membrane along the middle of the phospholipid bilayer
  15. glycolipids: carbohydrates covalently bonded to lipids
  16. glycoproteins: carbohydrates covalently bonded to proteins
  17. hypertonic: if a cell is in a solution that is _______ to the cell, the cell will lose water to its environment, shrivel, and probably die
  18. hypotonic: when a cell is in a solution that is ______ to the cell, water will enter the cell faster than it leaves, and will cause the cell to swell and burst
  19. integral proteins: ______ _______ penetrate the hydrophobic core of the lipid bilayer. their hydrophobic regions consist of one or more stretches of nonpolar amino acids, usually alpha helices.
  20. ion channels; gated channels: ____ ________ allow certaion ions to pass and they can function as _______ _____, where a stimulus causes them to open or close
  21. isotonic: if a cell without a wall is immersed in an environment that is ______ to the cell, there will be no net movement of water across the plasma membrane (water flows at the same rate in both directions)
  22. membrane potential: the _______ ________ is an energy source that affects the traffic of all charged substances across the membrane
  23. osmoregulation: _______ is the control of water balance
  24. osmosis: the diffusion of water across a selective permeable membrane is called _________
  25. passive transport: the diffuison of a substance across a biological membrane is called _______ _________ because the cell doesn't have to expend energy to make it happen
  26. peripheral proteins: _______ ________ aren't embedded in the lipid bilayer; they are appendages loosely bound to the surface of the membrane, often to exposed parts of integral proteins
  27. plasmolysis: when a cell is in a hypertonic environment, the cell will lose water to its surroundings, shrink, and its plasma membrane will pull away from the wall
  28. protein pump: the main electrogenic pump in plants, fungi and bacteria is a _______ _________, which actively transports hydrogen ions out of the cell
  29. selective permeability: the plasma membrane exhibits ________ ________; it allows some substances to cross it more easily than others
  30. sodium-potassium pump: a ______-_______ _____ exchanges sodium (Na+) for potassium (K+) across the plasma membrane of animal cells
  31. temperature buffer: cholesterol is a _______ _________ for the membrane; it resists changes in membrane fluidity that can be caused by changes in temperature
  32. tonicity: ________ is the ability of a solution to cause a cell to gain or lose water
  33. transport protein: some hydrophilic substances can avoid the lipid bilayer by passing through this
  34. turgid: _____ is a healthy state for most plant cells, where the cell wall exerts pressure to stop further intake of water
  35. voltages: all cells have _______ across their plasma membranes