Mutations Flashcards
What does the order of bases determine?
The order of amino acids
What do 3 bases in a row (a triplet) code for and what’s it called?
One amino acid, called the genetic code
What are different amino acids coded for by?
By different triplets
(e.g TAT = tyrosine, AGT = serine)
What does the order of bases (and so triplets) in the DNA of a gene determine?
The order of bases in its mRNA copy
What does the order of bases in an mRNA copy determine?
The order of amino acids in a protein
What are mutations and give an example?
Changes to the base sequence (order) of DNA
For example one base can be substituted (swapped) for one another one
What can one base substituted for another one cause and give an example?
Cause the triplet to change
e.g if C is substituted for A, GCT becomes GAT
So what do mutations also change?
The amino acids in the protein that the gene codes for
A change in the amino acids can cause?
A different protein to be produced
What can the different protein be?
Harmful
When do mutations happen?
Spontaneously (randomly)
What can increase how frequently mutations happen and what are they?
Mutagenic agents - factors that increase mutations, e.g UV radiation in sunlight
What can mutations cause and why?
Cancer, because cell division is controlled by proteins
If mutations occur in the genes for these proteins what can happen and what can it lead to?
They can alter the proteins so they no longer work, which can lead to uncontrolled cell division and development of a tumour (cancer)
What do mutations also cause?
Genetic disorders
