Biology (Chapter 4)

  1. Cytology
    The study of cells
  2. Cell Theory
    • The cell is the basic functional unit of life
    • All cells come from pre existing cells
    • All living things are composed of cells 
  3. Surface Area/Volume Ratio
    Cell Membrane/Cytoplasm require that cells remains small
  4. Prokaryotes
    • Simpler and smaller than eukaryotes and lack many of the internal features
    • Evolutionary beginnings are 3.6 billion years ago
  5. Eukaryotes 
    • Sized 10-100 Microns
    • Membrane-Bound Nucleus
  6. Plasma (Cell) Membrane
    Encloses the cell, separating it from its environment and regulating the molecular traffic that enters and exits the cell. 
  7. Nucleoid
    An area of dense cytoplasm that contains the hereditary information (DNA)
  8. Cytoplasm
    A semifluid solution composed mostly of water, dissolved molecules, including a large number of enzymes
  9. Bacterial Ribosome 
    • Roughly spherical strucutres suspended in the cytoplasm that function to manufacture proteins.
    • A bacterial cell contains thousands of ribosomes, which are smaller than eukaryotic ribosomes.
  10. Bacterial Cell Wall
    located outside of the plasma membrane, provides rigidity and support to the cell and determines it's shape 
  11. Peptidoglycan
    A polymer of amino sugars 
  12. Capsule
    Encloses the cell wall of some bacteria, compsed mostly of polysaccharide; they are well organized, compact, and not easily washed off
  13. Slime Layer
    gelatinous sheath, which can allow bacteria to stick to slick surfces; more diffuse, and readily removed
  14. Thyllakoid Membrane 
    Flat membranous disk that contain light sensitive pigments; only found in photosynthetic bacteria
  15. Pili/Fimbrae
    Project from the surface of some bacteria, shorter than flagellaand more threadlike, they help bacteria to adhere to one another, as well as to animal cells 
  16. Sex Pili
    Longer, hollow tubes that allow bacteria to pass DNA from cell to cell
  17. Plasmid
    Many Bacteria contain tiny, circular, extrachromosomal DNA, which often confer protective traits like antibiotic resistance or toxin and enzyme production
  18. Bacterial Flagellum
    Appendages that make some bacteria motile (capable of movement)
  19. Flagellin
    A protein that makes up flagella, it spins on its axis like a propeller, driving the cell along.
  20. um - Micrometer (Micron)
    1000 micrometers (um)= 1 millimeter
  21. Compound (Light) Microscope 
    A light source illuminates the object to be seen. That source can be a mirror, or the instrument can be self-illuminating. As light passes through the object, the lens nearest the object, called the objective lens, produces an enlarged image of the object in the primary image angle. The lens that you look into, the eyepiece, acts as a magnifier and produces an enlarged image of the image produced by the objective lens.
  22. Electron Microscope
    Reveals cell surface features; Specimens are not sectioned and electrons do not pass through them, rather the whole specimen is bombarded with electrons. Resolving power is no better than 10 nm.
  23. Animal Cell
    contain centrioles, which are not found in plant cells 
  24. Plant Cell
    Cell wall and chloroplasts, and central vacuoles
  25. Organelles
    Little organs found within the cytoplasm
  26. Nucelar Envelope (Membrane)
    Double membrane that surrounds the nucleus; it has numerous pores that connect the interior of the nucleus with the cytoplasm. 
  27. Chromatin (Chromatin Material)
    DNA+ protein that forms a fibrous complex (threads), found within the nucleus
  28. Chromosome 
    When a cell undergoes division, the chromatin super coils and condenses, to form these; each one contains one long molecule of DNA
  29. Nucleoplasm
    Water and dissolved substances found surrounding the chromatin within the nucleus, much like cytoplasm, but more protein rich 
  30. Nucleoli
    Singular nucleolus, usually one or more dense, spherical shaped bodies found in the nucleus; ribosomes are made here
  31. Ribosome
    The site of protein synthesis in both eukaryotes and prokaryotes, the most numerous organelle found within the cell
  32. Mitochondria
    • "The Powerhouse of the Cell"
    • Convert potential energy (chemical bond energy) in the form of food molecules into a form the cell can use, ATP.
  33. Cristae
    Typically small, about the size of many bacteria, they are composed of two membranes, an outer membrane, and an inner membrane that is quite extensive (shelf like) in animal cells
  34. ATP
    The energy rich molecule of the cell
  35. Plastid
    Organelles that are found only in plant cells and certain protists; photosynthesize or store materials
  36. Chloroplast
    Contains chlorophyll and is the site of photosynthesis found in plants and algae.
  37. Chlorophyll
    A green pigment, present in all green plants and in cyanobacteria, responsible for the absorption of light to provide energy for photosynthesis.
  38. Chromoplast
    Contain red, orange, or yellow carotenoids and are found in ripe tomatoes, carrots, peppers, etc
  39. Carotenoids 
    Any of a class of mainly yellow, orange, or red fat-soluble pigments, including carotene, which give color to plant parts such as ripe tomatoes and autumn leaves.
  40. Leucoplast
    colorless, storage depot for starch in plant cells 
  41. Endosymbiosis (Endosymbiont Hypothesis)
    Proposed in the early 1980's, suggests that mitochondria and chloroplasts chould have been free living prokaryotes that took up residence within another cell
  42. Endoplasmic Reticulum
    A network of membranes or channels flowing from the nuclear envelope, found throughout the cytoplasm, involved in modifying and transporting proteins
  43. Rough ER
    Covered with Ribosomes; produces proteins that are exported outside of the cell
  44. Smooth ER
    Areas that lack ribosomes; the site of phospholipid, steroid, and fatty acid synthesis (lipids)
  45. Golgi Apparatus
    • Consists of flattened membraneous sacs resembling a stack of pancakes, called cisterne and small membrane enclosed vesicles
    • Storage, chemical modification, and packaging of proteins for delivery outside of the cell
  46. Lysosome
    • Fluid filled, membrane bound vesicles, produced by the Golgi Apparatus
    • Contain digestive enzymes that breakdown proteins, carbohydrates, nucleic acids, and lipids
    • "Suicide Sacs"
  47. Peroxisome
    Small organelles with granular interior that breaks down toxic peroxides, such as hydrogen peroxide, with the aid of a catalase enztme
  48. Vacuole
    • Membrane enclosed organelles, specific for the function they carry out
    • Most prominent feature in many plant cells
  49. Contractile Vacuoles
    Act as tiny pumps, used in protist to remove excess water
  50. Food Vacuole
    Used for digestion
  51. Cytoskeleton
    Protein components found in the cytoplasm that maintain cell shape and support, and provide for various types of cell movement ; it extends from the nucleus to the plasma membrane. 
  52. Microfilaments 
    Long, thin, flexible, protein threads made from the protein actin
  53. Actin
    A protein that makes up microfilaments
  54. Intermediate Filaments
    Intermediate in diameter found only in multicellular organisms, stabilizing cell structure and resisting tension
  55. Keratin
    • A fibrous protein forming the main structural constituent of hair, feathers, hoofs, claws, horns, etc
  56. Integrin
    Receptors that mediate attachment between a cell and the tissues surrounding it
  57. Microtubules 
    Hollow protein tubes, having the largest diameter, made of tubulin
  58. Tubulin
    A protein that is the main constituent of the microtubules of living cells
  59. Flagella
    Usually found singly or in pairs
  60. Cilia
    • Shorter appendages, usually present in great numbers
    • They beat stiffly in one direction and recover flexibility in the other direction
  61. 9+2 Microtubule Arrangement 
    9 fused pairs of microtubules-called doublets forming an outer cylinder, and one pair of unfused microtubules running up the center
  62. Centrosome
    • Contains a pair of centrioles at right angle to each other
    • Major microtubule organizating centers (MTOC) for the cell
  63. Centriole
    Barrel-Shaped organelles, composed of microtubules function during cell division
  64. Cell Wall
  65. Cellulose 
  66. Plasmodesmata
    In plant cells, numerous membrane-lined channels, serve as openings between cell walls and plasma membranes allowing the exchange of water, plant hormones, ions, etc
  67. Tight Junctions
    • Connect the plasma membranes of adjacent animal cells in a sheet.
    • Specialized proteins link adjacent epithelial cells lining the intestines of the digestive tract. 
  68. Gap Junctions
    In animal cells, are made up of specialized protein channels (connexons), which facilitate communication between cells.
  69. Desmosomes
    Mechanically attach the cytoskeletons of adjacent cells, acting like "spot welds" or "rivets."
Card Set
Biology (Chapter 4)
Biology Notes