What can a random mutation lead to?

A random mutation means that there is a change in the base sequence of DNA. This could result in a different codon (sequence of 3 bases) and this means a different amino acid could be coded for. This means that the protein made from the different amino acids could be different.

There is three main effects of a random mutation and these are:

1. Damaging - if a different amino acid is coded for, a different protein could be made with a different active site so it can no longer fit the substrate so cannot perform its function (for example, amylase changes active site shape so can no longer break down starch)
2. No effect - many amino acids are 'degenerate' - This means that the same amino acid can be coded for by different codons. This means a change in the base sequence due to 'random mutation' can still lead to the same amino acid being made so there is no effect on the protein made
3. Beneficial - e.g. a change in amino acid coded for could result in a better fit of substrate into the active site of an enzyme

Hope this helps!