Cells Ch3

  1. Cells
    the structural units of all living things
  2. plasma membrane
    the outer boundary of the cell
  3. cytoplasm
    the intracellular fluid packed with organelles (small structures that perform specific cell functions)

    the cellular material surrounding the nucleus and enclosed by the plasma membrane
  4. tight junction
    series of integral protein molecules in the plasma membranes of adjacent cells fuse together, forming an impermeable junction that encircles the cell
  5. desmosomes
    "binding bodies"  anchoring functions - mechanical couplings scattered like rivets along the sides of abutting cells to prevent separation
  6. gap junction
    "nexus" - communicating junction b/w adjacent cells.  cells connected by hollow cylinders called connexons, composed of transmembrane proteins
  7. interstitial fluid
    • extracellular fluid that is derived from the blood. 
    • contains 1000's of ingredients, including amino acids, sugars, fatty acids, vitamins, regulatory substances - hormones and neurotransmitters, salts, and waste products
    • like a nutritious soup
  8. osmolarity
    the measure of the total concentration of solute particles

    *when solutions of different osmolarity are separated by a membrane, osmosis occurs until equilibrium is reached
  9. glycocalyx
    the fuzzy, sticky, carbohydrate-rich area at the cell surface
  10. tonicity
    the ability of a solution to cause a cell to shrink or swell by altering the cells internal water volume
  11. cytoplasm
    • "cell forming material"
    • cellular material b/w plasma membrane and nucleus, is the site of most cellular activities
  12. cytosol
    • viscous, semitransparent fluid in which other cytoplasmic elements are suspended
    • complex mixture w/properties of both a colloid and a true solution
  13. organelles
    • metabolic machinery of the cell
    • each type carries out specific function for the cell
  14. inclusions
    • chemical substances that may or may not be present, depending on cell type
    • eg-- stored nutrients, lipid droplets in fat cells, pigment (melanin) granules in certain skin and hair cells...
  15. free radical
    highly reactive chemicals w/unpaired electrons that can scramble the structure of biological molecules
  16. centrioles
    small tubes formed by microtubules
  17. chromatin
    structures in the nucleus that carry the hereditary factors (genes)
  18. chromosomes
    • barlike bodies of tightly coiled chromatin
    • visible during cell division
  19. semiconservative replication
    the mechanism of DNA replication
  20. gene
    segment of DNA w/blueprint for one polypeptide
  21. genetic code
    each 3-base sequence on DNA is represented by a codon
  22. codon
    complementary 3-base sequence on mRNA
  23. anticodon
    3-base sequence complementary to the mRNA codon
  24. triplet
    each sequence of three-base
  25. transfer RNA (tRNA)
    short-chain RNA molecules that transfer amino acids to the ribosome
  26. ribosomal RNA (rRNA)
    constituent of ribosome, exists within the ribosomes of cytoplasm and assists in protein synthesis
  27. messenger RNA (mRNA)
    long nucleotide strands that reflect the exact nucleotide sequences of the genetically active DNA and carry the DNA's message
  28. apoptosis
    a process of controlled cellular suicide, eliminates cells that are unneeded, stressed, or aged
  29. anaplasia
    an= without; plas= to grow

    abnormalities in cell structure and loss of differentiation

    example- cancer cells typically lose the appearance of parent cells and come to resemble undifferentiated or embryonic cells
  30. dysplasia
    dys= abnormal

    a change in cell size, shape, or arrangement due to chronic irritation or inflammation (infections, etc)
  31. hypertrophy
    • growth of an organ or tissue due to an increase in the size of its cells
    • normal response of skeletal muscle cells when they are challenged to lift excessive weight
    • differs from hyperplasia, which is an increase in size due to an increase in cell #
  32. liposomes
    • hollow microscopic sacs formed of phospholipids that can be filled w/a variety of drugs
    • serve as multipurpose vehicles for drugs, genetic material, and cosmetics
  33. mutation
    • a change in DNA base sequence that may lead to incorporation of incorrect amino acids in particular positions in the resulting protein
    • the affected protein may remain unimpaired or may function abnormally or not at all, leading to disease
  34. necrosis
    • death of a cell or group of cells due to injury or disease
    • acute injury causes cells to swell and burst, and induces the inflammatory response (this is uncontrolled cell death, in contrast to apoptosis)
  35. osmosis
    diffusion of a solvent through a membrane from a dilute solution into a more concentrated one
Card Set
Cells Ch3
vocab terms ch3