Cellular Control Flashcards
What is a somatic mutation?
-mutations associated with mitotic division
-may be associated with development of cancerous tumours
-these mutations are not passed on to offspring
What mutations may be inherited by offspring?
-mutations associated with meiosis and gamete formation
What are the 2 main classes of DNA mutation?
-point mutation
-insertion or deletion mutation
What is a point mutation?
List the 3 types of point mutation?
-when one base pair replaces (is substituted for) another
3 types
-silent,missense,nonsense
What is a silent mutation?
-it is a point mutation involving a change to the base triplet, where the triplet still codes for the same amino acid
-the primary structure of the protein and therefore the secondary and tertiary structure is not altered
What is a missense mutation?
-a change to the base triplet sequence that leads to a change in the amino acid sequence in a protein
-this point mutation may have a significant effect on the protein produced by altering the primary structure this leads to a change of the tertiary structure of the protein thus altering its shape and preventing it from carrying out its normal function
What is an example of a condition that results from a missense mutation?
-sickle cell anaemia
What is a nonsense mutation ?
-a point mutation that alters a base triplet so that it becomes a stop triplet
-this will severely disrupt the structure of a protein
-the genetic disease muscular dystrophy is the result of a nonsense mutation
What is an insertion or deletion mutation ?
-when one or more nucleotides are inserted or deleted from a length of DNA
-This will cause a frame shift (if not added in multiples of 3) a frame shift will severely disrupt the amino acid sequence. This will alter the primary and therefore the tertiary structure
What do insertions or deletions of a triplet of base pairs result in?
-the addition or loss of an amino acid
