Cellular Control Flashcards
What are gene mutations?
Gene mutations are caused by mistakes during DNA replication as well as a number of factors in the environment.
What environmental factors cause gene mutations?
UV light Pollutants Chemicals in cigarette smoke Radiation Oxidants
What are mutagens?
They cause changes to the bases in the DNA, so that the bases are deleted, inserted or substituted.
What happens to most mutations?
Most mutations are repaired by proteins inside the nucleus.
What happens if a mutation is not repaired?
If a mutation is not repaired, it can lead to changes in the structure of proteins.
What do point mutations do?
Point mutations in the genetic sequence change the triplet codon.
What does a codon do?
Each codon codes for a particular amino acid
Why are mutations often neutral?
As most amino acids have two or more codons, the mutations can often be neutral.
What are frameshift mutations?
Insertion and deletion
What do frameshift mutations do?
They alter the point from where the codon is read. These are more likely to alter the amino acid sequence and so change the way in which the protein folds.
What is a beneficial mutation?
If the new folding improves the function of the protein, it often improves the characteristic of that protein.
What is a harmful mutation?
Often the change in protein folding results in a non-functioning or truncated (smaller) protein.
