cellular control key bits n bobs Flashcards
what determines the impact of the new amino acids that may be inserted as a result of a mutation?
- the position and involvemet of the amino acid R group interactions within the protein
what is a point mutation?
- a mutation to a single nucleotide of the DNA, eg where a nucleotide is switched for another
- eg a substitution
explain the effect of the frameshift?
- usually caused by insertion and deletion
- changes the number of bases in the DNA sequences.
- changes the way every successive codon is read after the point of mutation.
state and explain the 4 types of chromosomal mutations that involve changing the number or structure of whole chromosomes.
translocation –> part of one chromosome that breaks off attaches to another homologous chromosomes.
inversion -> part of the chromosome is reversed.
duplication -> the section of a chromosome is duplicated.
deletion –> loss of all parts of chromosome within a cell.
what is a chromosomal mutation?
a change in the structure or number of a whole chromosome.
give an example of a harmful mutations
sickle cell anaemia
- this results in the cell not containing the correct amount of O2 for respiration
what is a missense mutation?
these mutations result in the incorporation of an incorrect amino acid into the primary structure when the protein is synthesised.
- it usually causes proteins to be less efficient in their function
what is a conservative mutation?
when an amino acid change leads to an amino acid being coded for that was SIMILAR to the original (ie mutation is less severe)
what is a non conservative mutation?
- when the new coded amino acid has different properties from the original.
what do mutagenic agents do?
- they increase the frequency of mutations
what can causes mutations (ie changes tot he DNA sequences?
- exposure to chemicals (ie UV, Bromine etc)
- radio/chemotherapy.
- DNA replication
- chromosomal mutations of meiosis.
