chap 4 - flashcards - mader bio.txt

  1. actin filament
    Muscle protein filament in a sarcomere; its movement shortens the sarcomere- yielding muscle contraction. Actin filaments play a role in the movement of the cell and its organelles.
  2. Bacillus
    A rod-shaped bacterium; also a genus of bacteria- Bacillus.
  3. basal body
    A cytoplasmic structure that is located at the base of�and may organize�cilia or flagella.
  4. Capsule
    Gelatinous layer surrounding the cells of blue-green algae and certain bacteria.
  5. Cell
    Smallest unit that displays the properties of life; composed of organelle-containing cytoplasm surrounded by a plasma membrane.
  6. cell envelope (of prokaryotes)
    In a prokaryotic cell- the portion composed of the plasma membrane- the cell wall- and the glycocalyx.
  7. cell theory
    One of the major theories of biology- which states that all organisms are made up of cells; cells are capable of self-reproduction and come only from preexisting cells.
  8. cell wall
    Structure that surrounds a plant- protistan- fungal- or bacterial cell and maintains the cell's shape and rigidity.
  9. central vacuole (of plant cell)
    In a plant cell- a large- fluid-filled sac that stores metabolites. During growth- it enlarges- forcing the primary cell wall to expand and the cell surface-area-to-volume ratio to increase.
  10. Centriole
    Cell organelle- existing in pairs- that occurs in the centrosome and may help organize a mitotic spindle for chromosome movement during animal cell division.
  11. Centrosome
    Central microtubule organizing center of cells. In animal cells- it contains two centrioles.
  12. Chloroplast
    Membrane bounded organelle in algae and land plants with chlorophyll-containing membranous thylakoids; where photosynthesis takes place.
  13. Chromatin
    Network of DNA strands and associated proteins observed within a nucleus that is not dividing.
  14. Chromoplast
    Plastid in land plants responsible for orange- yellow- and red color of plants- including the autumn colors in leaves.
  15. Chromosome
    An observable structure that results when chromatin condenses and coils- each species has a particular number of chromosomes that is passed on to the next generation.
  16. Cilium
    Short- hairlike projections from the plasma membrane- occurring usually in larger numbers (cilia).
  17. Coccus
    A spherical-shaped bacterium.
  18. conjugation pili
    In a bacterium- elongated- hollow appendage used to transfer DNA to other cells.
  19. Contrast
    In magnification with a microscope- brightness differences between objects.
  20. Cristae
    Short- fingerlike projections formed by the folding of the inner membrane of mitochondria.
  21. Cyanobacteria
    Photosynthetic bacterium that contains chlorophyll and releases oxygen; formerly called a blue-green alga.
  22. Cytoplasm
    Contents of a cell between the nucleus (nucleoid) region of bacteria and the plasma membrane.
  23. Cytoskeleton
    Internal framework of the cell- consisting of microtubules- actin filaments- and intermediate filaments.
  24. endomembrane system
    Cellular system that consists of the nuclear envelope- endoplasmic reticulum- Golgi apparatus- and vesicles.
  25. endoplasmic reticulum (ER)
    System of membranous saccules and channels in the cytoplasm- often with attached ribosomes.
  26. endosymbiotic theory
    Explanation of the evolution of eukaryotic organelles by phagocytosis of prokaryotes.
  27. eukaryotic cell
    Type of cell that has a membrane bounded nucleus and membranous organelles; found in organisms within the domain Eukarya.
  28. Fimbriae
    Small- bristlelike fiber on the surface of a bacterial cell- which attaches bacteria to a surface; also fingerlike extension from the oviduct near the ovary.
  29. flagellum (flagella)
    Long- slender extension used for locomotion by some bacteria- protozoans- and sperm.
  30. Gene
    Unit of heredity existing as alleles on the chromosomes; in diploid organisms- typically two alleles are inherited�one from each parent.
  31. Glycocalyx
    Gel-like coating outside the cell wall of a bacterium. If compact- it is called a capsule; if diffuse- it is called a slime layer.
  32. Golgi apparatus
    Organelle consisting of sacs and vesicles that processes- packages- and distributes molecules about or from the cell.
  33. Granum
    Stack of chlorophyll-containing thylakoids in a chloroplast.
  34. inclusion body
    In a bacterium- stored nutrients for later use.
  35. intermediate filament
    Ropelike assemblies of fibrous polypeptides in the cytoskeleton that provide support and strength to cells; so called because they are intermediate in size between actin filaments and microtubules.
  36. Leucoplast
    Plastid- generally colorless- that synthesizes and stores starch and oils.
  37. Lysosome
    Membrane-bounded vesicle that contains hydrolytic enzymes for digesting macromolecules.
  38. Magnification
    Using a microscope- enlarging an object for viewing.
  39. Matrix
    Unstructured semifluid substance that fills the space between cells in connective tissues or inside organelles.
  40. Mesosome
    In a bacterium- plasma membrane that folds into the cytoplasm and increases surface area.
  41. Microtubule
    Small- cylindrical organelle composed of tubulin protein around an empty central core; present in the cytoplasm- centrioles- cilia- and flagella.
  42. Mitochondrion
    Membrane-bounded organelle in which ATP molecules are produced during the process of cellular respiration.
  43. motor molecule
    Protein that moves along either actin filaments or microtubules and translocates organelles.
  44. nuclear envelope
    Double membrane that surrounds the nucleus in eukaryotic cells and is connected to the endoplasmic reticulum; has pores that allow substances to pass between the nucleus and the cytoplasm.
  45. nuclear pore
    Opening in the nuclear envelope that permits the passage of proteins into the nucleus and ribosomal subunits out of the nucleus.
  46. Nucleoid
    Region of prokaryotic cells where DNA is located; it is not bounded by a nuclear envelope.
  47. Nucleolus
    Dark-staining- spherical body in the nucleus that produces ribosomal subunits.
  48. Nucleoplasm
    Semifluid medium of the nucleus containing chromatin.
  49. Organelle
    Small- often membranous structure in the cytoplasm having a specific structure and function.
  50. Peroxisome
    Enzyme-filled vesicle in which fatty acids and amino acids are metabolized to hydrogen peroxide that is broken down to harmless products.
  51. plasma membrane
    Membrane surrounding the cytoplasm that consists of a phospholipid bilayer with embedded proteins; functions to regulate the entrance and exit of molecules from cell.
  52. Plasmid
    Extrachromosomal ring of accessory DNA in the cytoplasm of bacteria.
  53. Plastid
    Organelles of plants and algae that are bounded by a double membrane and contain internal membranes and/or vesicles (i.e.- chloroplasts- chromoplasts- leucoplasts).
  54. Polyribosome
    String of ribosomes simultaneously translating regions of the same mRNA strand during protein synthesis.
  55. prokaryotic cell
    Lacking a membrane-bounded nucleus and organelles; the cell type within the domains Bacteria and Archaea.
  56. Pseudopod
    Cytoplasmic extension of amoeboid protists; used for locomotion and engulfing food.
  57. Resolution
    Capability of a microscope to distinguish the separate parts of an object.
  58. Ribosome
    RNA and protein in two subunits; site of protein synthesis in the cytoplasm.
  59. rough ER
    Membranous system of tubules- vesicles- and sacs in cells; has attached ribosomes.
  60. Secretion
    Release of a substance by exocytosis from a cell that may be a gland or part of a gland.
  61. signal peptide
    Sequence of amino acids that binds with a SRP- causing a ribosome to bind to ER.
  62. smooth ER
    Membranous system of tubules- vesicles- and sacs in eukaryotic cells; lacks attached ribosomes.
  63. Spirillum
    Long- rod-shaped bacterium that is twisted into a rigid spiral; if the spiral is flexible rather than rigid- it is called a spirochete.
  64. Spirochete
    Long- rod-shaped bacterium that is twisted into a flexible spiral; if the spiral is rigid rather than flexible- it is called a spirillum.
  65. Stroma
    Fluid within a chloroplast that contains enzymes involved in the synthesis of carbohydrates during photosynthesis.
  66. surface-area-to-volume ratio
    Ratio of a cell's outside area to its internal volume.
  67. Thylakoid
    Flattened sac within a granum whose membrane contains chlorophyll and where the light reactions of photosynthesis occur.
  68. Vacuole
    Membrane-bounded sac- larger than a vesicle; usually functions in storage and can contain a variety of substances. In plants- the central vacuole fills much of the interior of the cell.
  69. Vesicle
    Small- membrane-bounded sac that stores substances within a cell.
Card Set
chap 4 - flashcards - mader bio.txt
BIO - Chap 4 Cell Structure