biology test

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biology test
2012-10-01 11:46:30
bio 101 test

cecil college (aliu)
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  1. ligand
    the signaling molecule
  2. receptor protein
    the molecule to which the receptor binds  -may be on the plasma membrane or within the cell
  3. signal transduction
    the events within the cell that occur in response to a signal
  4. Direct contact (cell communication)
    molecules on the surface of one cell are recognized by receptors on the adjacent cell
  5. Paracrine signaling
    signal released from a cell has an effect on neighboring cells
  6. Endocrine signaling
    hormonesreleased from a cell affect other cells throughout the body
  7. Synaptic signaling
    nervecells release the signal (neurotransmitter)which binds to receptors on nearby cells
  8. Phosphorylation
    acommon way to change the activity of a protein.
  9. protein kinase
    an enzyme that adds a phosphate to a protein
  10. phosphatase
    an enzyme that removes a phosphate from a protein
  11. cell surface receptor
    receptor – located on the plasma membrane to bind a ligand outside the cell
  12. channel linked receptors
    ion channel that opens in response to a ligand
  13. enzymatic receptors
    – receptor is an enzyme that is activated by the ligand
  14. G protein-coupled receptor
    a G-protein (bound to GTP) assists in transmitting the signal
  15. G-protein-coupled receptor (GPCRs)
    – receptors bound to G proteins
  16. G-protein
    activatesan effector protein (usually an enzyme)
  17. g protein second messenger
    generates the cellular response to the original signal
  18. steroid hormones
    have a nonpolar, lipid-soluble structure usuallyaffect regulation of gene expression
  19. major histocompatibility complex
    proteins are used by cells to distinguish “self” from “non-self”
  20. glycolipids
    are commonly used as tissue-specific markers
  21. tight junctions
    createsheets of cells
  22. anchoring junctions
    connect the cytoskeletons of adjacent cells
  23. communicating junctions
    permit small molecules to pass between cells
  24. gap junctions
    in animal cells
  25. plasmodesmata
    in plant cells
  26. globular proteins
    inserted in the lipid bilayer
  27. phospholipids
    arranged in a bilayer
  28. glycerol
    a3-carbon polyalcohol acting as a backbone for the phospholipid
  29. 2 fattyacids/ phosphate group
    attached to the glycerol
  30. Peripheral membrane proteins
    anchored to a phospholipid in one layer of the membrane  -possess nonpolar regions that are inserted in the lipid bilayer  -are free to move throughout one layer of the bilayer
  31. Integral membrane proteins
    span the lipid bilayer (transmembrane proteins)  -nonpolar regions of the protein are embedded in the interior of the bilayer  -polar regions of the protein protrude from both sides of the bilayer
  32. transmembrane domain
    regionof the protein containing hydrophobic amino acids
  33. b-barrel
    interior is polar and allows water and small polar molecules to pass through the membrane
  34. Passive  transport
    is movement of molecules through the membrane in which  -no energy is required  -molecules move in response to a
  35. Diffusion
    ismovement of molecules from high concentration to low concentration
  36. Selective permeability:
    integral membrane proteins allow the cell to be selective about what passes through the membrane.
  37. Channel proteins
    have a polar interior allowing polar molecules to pass through.
  38. Carrier proteins
    bind to a specific molecule to facilitate its passage.
  39. ion channels
    allow the passage of ions (charged atoms or molecules) which are associated with water
  40. gated channels
    are opened or closed in response to a stimulus
  41. Facilitated diffusion
    is movement of a molecule from high to low concentration with the help of a carrier protein.
  42. Osmosis
    is the movement of water from an area of high to low concentration of water
  43. hypertonic solution
    has a higher solute concentration
  44. hypotonic solution
    has a lower solute concentration
  45. osmosis water through------ard the hypertonic solution.
  46. Some cells use --------- in which water is ejected through contractile vacuoles.
  47. ---------------keeping the cell isotonic with their enviroment
    Isosmotic regulation
  48. Plantcells use -to push the cell membrane against thecell wall and keep the cell rigid
  49. Active transport
    requiresenergy – ATP is used directly or indirectly to fuel active transport
  50. uniporters
    – move one molecule at a time
  51. symporters
    move two molecules in the same direction
  52. antiporters
    movetwo molecules in opposite directions
  53. Sodium-potassium (Na+-K+) pump
    an active transport mechanism  -uses an antiporter to move 3 Na+ out of the cell and 2 K+ into the cell
  54. Coupled transport
    uses the energy released when a molecule moves by diffusion to supply energy to active transport of a different molecule  -a symporter is used
  55. endocytosis
    – movement of substances into the cell
  56. exocytosis
    movement of materials out of the cell
  57. pinocytosis
    thecell takes in only fluid
  58. receptor-mediated endocytosis
    specificmolecules are taken in after they bind to a receptor
  59. Surface area-to-volume ratio
    as a cell increases in size, the volume increases 10x faster than the surface area
  60. Light microscopes
    canresolve structures that are 200nm apart
  61. Electron microscopes
    canresolve structures that are 0.2nm apart
  62. Probe microscopes
    canresolve structures to the atomic size.
  63. Prokaryotic cells
    lacka membrane-bound nucleus.
  64. Archaean
    cellwalls lack peptidoglycan
  65. DNAis organized with proteins to form -and further packaged into-
    •  nucleosomes
    • chromatin
  66. Ribosomes
    thesite of protein synthesis in the cell
  67. Rough endoplasmic reticulum (RER)
    synthesis of proteins to be secreted, sent to lysosomes or plasma membrane
  68. Smooth endoplasmic reticulum (SER)
    -relatively few ribosomes attached  -functions:  -synthesis of membrane lipids  -calcium storage  -detoxification of foreign substances
  69. Golgi apparatus
    flattened stacks of interconnected membranes  -packaging and distribution of materials to different parts of the cell
  70. Lysosomes
    destroycells or foreign matter that the cell has engulfed by phagocytosis
  71. Vacuoles
    membrane-bound structures with various functions depending on the cell type
  72. Peroxisomes
    contain oxidative enzymes and catalase
  73. Chloroplasts
    organelles present in cells of plants and some other eukaryotes  -contain chlorophyll for photosynthesis
  74. thylakoids
    are membranous sacs within the inner membrane
  75. grana
    are stacks of thylakoids
  76. Endosymbiotic Theory
    proposedthat eukaryotic organelles evolved through a symbiotic relationship
  77. 9-2 structure
    9pairs of microtubules surrounded by 2 central microtubules
  78. Extracellular matrix (ECM)
    composed of glycoproteins and fibrous proteins such as collagen  -connected to the cytoplasm via integrin proteins present in the plasma membrane