cell bio

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cell bio
2010-03-30 12:40:10
cell division cycle

chapter 18
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  1. anaphase
    state of mitosis during which the two sets of chromosomes separate and move away from each other. composed of anaphase A (chromosomes move toward the two spindle poles) and anaphase B (spindle poles move apart)
  2. anaphase promoting comples (APC)
    a protein complex that promotes the destruction of sepcific proteins, by catalyzing their ubiquitylation. it is a crucial component of the cell cyle control system
  3. apoptosis
    normal, benign type of programmed cell death in which a cell shrinks, fragments its DNA, and alters its surface so as to activate the cells phagocytosis by macrophages
  4. aster
    star shaped system of microtubules emanating from a centrosome or from a pole of a mitotic spindle
  5. bc12 family
    family of intracellular proteins that either promote or inhibit apoptosis by regulating the activation of caspases
  6. bi-orientation
    the symmetrical alighnment of sister chromatid pairs on the mitotic spindle, such that one chromatid is attached to one spindle pole and the other chromatid to the opposite pole
  7. caspase
    a family of proteases. members of the family are activated as part of the pathway leading to apoptosis
  8. cdk (cyclic dependent prtein kinase)
    protein kinase that has to be complexed with a cyclin protein in order to act. different cdk-cyclin complexes trigger different steps in the cell division cycle by phosphorylatng specific target proteins
  9. cdk inhibitor protein
    protein that inhibits cyclin-cdk complexes, primarliy to inhibit progress through the g1 and s phases of the cell cycle
  10. cell cycle
    reproductive cycle of the cell; the orderly sequence of events by which a cell duplicated its contents and divides into two
  11. cell cycle control system
    network of regulatory proteins that governs progression of a eucaryotic cell through the cell cycle
  12. centrosome
    centrally located organelle of animal cells that is the primary microtubule-organizing center and separates to form the two spindle poles during mitosos. in most ansimal cells it contains a pair of centrioles
  13. centrosome cycle
    duplication of the centrosome (during interphase) and separtation of the two new centrosomes (at the beginning of mitosis) to form the poles of the mitotic spindle
  14. checkpoint
    point in the eucaryotic cell division cell cyle where progress through the cycle can be halted until conditions are suitable for the cell to proceed to the next stage
  15. chromosome condensation
    process by which a chromosome becomes packed into a more compact structure prior to M phase of the cell cycle
  16. cohesin
    protein complx that forms a ring that holds sister chromatids together after DNA has been replicated in the cell cycle
  17. condensin
    protein complexes wiht a ring-like structure that help carryout chromosome condensation
  18. cyclin
    protein that periodically rises and falls in concentration in step with the eucarytoic cell cycle. cyclins activate specific protein kinases and thererby help control progression from one stage of the cell cycle to the next
  19. cytokinesis
    division of the cytoplasm of a plant or animal cell into two, as distinct from the division of its nucleus (which is mitosis)
  20. G1 - Cdk
    cyclin dependent kinase whose activity drives the cell through the g1 phase
  21. G1 S-Cdk
    cyclin dependent kinase whose activity triggers entry into S phase of the cell cycle
  22. G1 phase
    gap 1 phase of teh eucaryotic cell cycle, between the end of cytokinesis and the start of DNA synthesis
  23. G2 phase
    gap 2 phase of the eucaryotic cell cycle, between the end of DNAsynthesis and the beginning of mitosis
  24. growth factor
    extracellular polypeptide signaling molecule that stimulates a cell to grow or proliferate. examples are epidermal growth factor (EGF) and platelet-derived growth factor (PDGF)
  25. interphase
    long period of the cell cycle between one mitosis and the next. includes g1 phase, s phase, and g2 phase
  26. kinetochore
    complex protein-containing structure on a mitotic chromosome to which microtubels attach. it forms on th epart of the chromosome known as the centromere
  27. M-Cdk
    active protein complex formed at the start of the M phase of the cell cycle by an M-cyclin and the mitotic cylindependent protein kinase (Cdk)
  28. M cyclin
    cyclin protein that binds to mitotic Cdk to form M-Cdk at the start of M phase of the cell cycle
  29. M phase
    period of the eucaryotic cell cycle during which the nucleus and cytoplasm divide
  30. metaphase
    stage of mitosis at which chromosomes are firmly attached to the mitotic spindle at its equator but have not yet segregated toward opposite poles
  31. mitogen
    an extracellular signal molecule that stimulates cell proliferation
  32. mitosis
    division of the nucleus of a eucaryotic cell, which involves condensation of the DNA into visible chromosomes
  33. mitotic spindle
    array of microtubles and associated molecules that forms between the opposite poles of a eucaryotic cell during mitosis; during the separation of the duplicated chromosomes, the spindle serves to move the two chromose sets apart
  34. origin recognition complex (ORC)
    large protein complex that is bound to the DNA at origins of replication in eucaryotic chromosomes throughout the cell cycle
  35. p53
    regulatory protein that responds to the presence of DNA damage, preventing the cell from entering S phase until the damage has been repaired
  36. phragomoplast
    structure made of microtubles and membrane vesicles that forms in the equatorial region of a dividing plant cell from which the membrane that divides the daughter cells will be made
  37. prometaphase
    state of mitosis that precedes metaphase
  38. prophase
    first stage of mitosis during which the chromosomes are condensed by not yet attached to a mitotic spindle. also a superficially similar state in meiosis.
  39. S phase
    period during a eucaryotic cell cycle in which DNA is sythesized
  40. sister chromatid
    one copy of a chromosome formed by DNA replication that is still joined at the centromere to the other copy, the pair of chromatids being known as sister chromatids
  41. spindle pole
    one of two centromsomes ina cell undergoing mitosis. microtubles radiation from these centrosomes form the mitotic spindle
  42. survival factor
    extracellular signaling molecule that must be present to prevent apoptosis
  43. telephase
    final stage of mitosis in which the two sets of separated chromosomes decondense and become enclosed by nuclear envelopes