6+7. mutations and CFTR

• 3 types of mutation?

  base:

  • substitution: correct base may be changed for wrong one
  • deletion: correct base is missed out
  • insertion/addition: extra unwanted base is added

  could cause frame shift, changes in triplet that follow mutation (huge effect !)
• how do gene mutations affect proteins?

  • mutation gives rise to change in base sequence on DNA
  • may change sequence of codons on mRNA
  • different aa coded for= change in sequence of aa in pp chain
  • different R groups can cause different bonds in folding secondary/tertiary structure
  • specific 3d shape may be altered or no even produce a protein
  • protein won't correctly carry out function