How does a point mutation result in a defective protein consisting of a.a. sequence different from wild type?

Question

Thanks for the help!

Answer 1

A point mutation, or single base substitution, is a type of mutation that causes the replacement of a single base nucleotide with another nucleotide

For example, sickle-cell disease is caused by a single point mutation (a missense mutation) in the beta-hemoglobin gene that converts a GAG codon into GTG, which encodes the amino acid valine rather than glutamic acid.