L10-12 quiz

• _ are enzymes that regulate cell division by phosphorylating proteins

  CDK (cyclin-dependent kinases)
• CDK activity is regulated by _ binding


  cyclin
• _ are external factors capable of governing passage through the G1 checkpoint (restriction point)

  growth factors
• cyclin-dependent kinase is recycled for use in the subsequent cell cycle
• not all tumours are malignant, some remain localised and are _

  benign
• cancer cells differ from normal cells as they demonstrate anchorage _ of growth

  independence
• cancer cells differ from normal cells as they demonstrate loss of _ inhibition of growth

  contact
• retinoblastoma protein is a _

  tumour suppressor
• retinoblastoma inhibits the cell cycle at the _ checkpoint

  G1
• retinoblastoma protein regulates the expression of several S phase genes including _, but doesn't act directly on Cdks

  cyclins
• a point mutation causing loss of protein function would cause the cell cycle to _

  arrest
• changes associated with proto-oncogenes becoming oncogenes:

  • movement to new location
  • amplification
  • mutation in controlling element causing over-expression
  • point mutation leading to hyperactive protein
• Ras oncogene:

  • codes for a molecular switch (small G protein in growth promoting pathway)
  • found in bladder cancers
  • transforms mouse 3T3 cells
  • stimulates cell division
• when DNA damage is too great to be repaired p53 induces _

  apoptosis