Biology Chapter 5

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  1. What is a Phospholipid?
    Similar in structure to a fat, but having only two fatty acids attached to the glycerol backbone, with the third space linked to a phosphorylated molecule; contains a polar hydrophilic “head” end (phosphate group) and a nonpolar hydrophobic “tail” end (fatty acids).
  2. What is Signal Transduction?
    The events that occur within a cell on receipt of a signal, ligand binding to a receptor protein. Signal transduction pathways produce the cellular response to a signaling molecule.
  3. What is Selective Permeability?
    means that the cell membrane has some control over what can cross it, so that only certain molecules either enter or leave the cell.  Molecules can cross the plasma membrane in three main ways.
  4. What is a Transport Protein?
    transport protein (variously referred to as a transmembrane pump,transporter protein, escort protein, acid transport protein, cationtransport protein, or anion transport protein) is a protein that serves the function of moving other materials within an organism.
  5. What is Diffusion?
    The net movement of dissolved molecules or other particles from a region where they are more concentrated to a region where they are less concentrated.
  6. What is Concentration Gradient?
    a gradual change in the concentration of solutes in a solution as a function of distance through a solution.
  7. What is Equilibrium?
    A stable condition; the point at which a chemical reaction proceeds as rapidly in the reverse direction as it does in the forward direction, so that there is no further net change in the concentrations of products or reactants. In ecology, a stable condition that resists change and fairly quickly returns to its original state if disturbed by humans or natural events.
  8. What is Osmosis?
    The diffusion of water across a selectively permeable membrane (a membrane that permits the free passage of water but prevents or retards the passage of a solute); in the absence of differences in pressure or volume, the net movement of water is from the side containing a lower concentration of solute to the side containing a higher concentration.
  9. What is Isotonic Solution?
    A solution having the same concentration of solutes as the cell. A cell in an isotonic solution takes in and loses the same amount of water.
  10. What is Hypertonic Solution?
    A solution with a higher concentration of solutes than the cell. A cell in a hypertonic solution tends to lose water by osmosis.
  11. What is Hypotonic Solution?
    A solution with a lower concentration of solutes than the cell. A cell in a hypotonic solution tends to take in water by osmosis.
  12. What is a Channel Protein?
    is a protein that allows the transport of specific substances across a cell membrane.
  13. What are Gated Channels?
    Gated channels are simply protein channels that only open under certain conditions.  Like a tollbooth gate only opens after you have paid, gated channels only open after something has happened.  That something could be an electrical event or a chemical event.
  14. What is a Carrier Protein?
    A membrane protein that binds to a specific molecule that cannot cross the membrane and allows passage through the membrane.
  15. What is facilitated diffusion?
    Carrier-assisted diffusion of molecules across a cellular membrane through specific channels from a region of higher concentration to one of lower concentration; the process is driven by the concentration gradient and does not require cellular energy from ATP.
  16. What is Active Transport?
    The pumping of individual ions or other molecules across a cellular membrane from a region of lower concentration to one of higher concentration (i.e., against a concentration gradient); this transport process requires energy, which is typically supplied by the expenditure of ATP.
  17. What is Exocystosis?
    A type of bulk transport out of cells in which a vacuole fuses with the plasma membrane, discharging the vacuole's contents to the outside.
  18. What is Endocytosis?
    The uptake of material into cells by inclusion within an invagination of the plasma membrane; the uptake of solid material is phagocytosis, and that of dissolved material is pinocytosis.
  19. What is Phagocytosis?
    Endocytosis of a solid particle; the plasma membrane folds inward around the particle (which may be another cell) and engulfs it to form a vacuole.
  20. What is Pinocystosis?
    The process of fluid uptake by endocytosis in a cell.
  21. What is Cell Signaling?
    part of a complex system of communication that governs basic cellular activities and coordinates cell actions. The ability of cells to perceive and correctly respond to their microenvironment is the basis of development, tissue repair, and immunity as well as normal tissue homeostasis.
  22. What is First Messenger?
    a hormone that binds to a receptor on the surface cell and, in so doing, communicates with intracellular metabolic processes.
  23. What is a second Messenger?
    molecule inside cells that acts to transmit signals from a receptor to a target. The term second messenger was coined upon the discovery of these substances in order to distinguish them from hormones and other molecules that function outside the cell as “first messengers” in the transmission of biological information. Many second messenger molecules are small and therefore diffuse rapidly through the cytoplasm, enabling information to move quickly throughout the cell.
  24. What is Cell Junction?
    (or intercellular bridge ) is a type of structure that exists within the tissue of some multicellular organisms, such as animals. Cell junctions consist of multiprotein complexes that provide contact between neighbouring cells or between a cell and the extracellular matrix.
  25. What is an Anchoring Junction?
    The main purpose of an anchoring junction is to hold cells together at a mass of proteins called a plaque. Anchoring junctions are made up of three different proteins: cadherins, which form homodimers with each other in the membranes of adjacent cells, and α-catenin and β-catenin. Anchoring junctions have two forms.
  26. What is a Desmosome?
    Desmosomes are intercellular junctions of epithelia and cardiac muscle. They resist mechanical stress because they adopt a strongly adhesive state in which they are said to be hyper-adhesive and which distinguishes them from other intercellular junctions
  27. What is an Adhering Junction?
    defined as a cell junction whose cytoplasmic face is linked to the actin cytoskeleton. They can appear as bands encircling the cell (zonula adherens) or as spots of attachment to the extracellular matrix (adhesion plaques).
  28. What is Cadherin?
    One of a large group of transmembrane proteins that contain
  29. What is a Tight Junction?
    Region of actual fusion of plasma membranes between two adjacent animal cells that prevents materials from leaking through the tissue.
  30. What is a Gap Junction?
    or nexus or macula communicans is a specialized intercellular connection between a multitude of animal cell-types. It directly connects the cytoplasm of two cells, which allows various molecules and ions to pass freely between cells.
  31. What is Plasmodesmata?
    In plants, cytoplasmic connections between adjacent cells.
Card Set:
Biology Chapter 5
2014-09-23 20:16:09
Biology Chapter
Biology Chapter 5
Biology Chapter 5
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