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Effects of Mutations

01Effects of Mutations

DNA to polypeptide

This section covers how a change in DNA base sequence can alter the amino acid sequence of an encoded polypeptide.

Linking DNA sequence to polypeptide

The order of bases in a gene determines the order of amino acids in its encoded polypeptide. A mutation alters the DNA base sequence, so the encoded amino acid sequence may also be altered.

The outcome is not the same for every mutation. Some make no difference to the amino acid sequence, some produce only a limited change, and others result in a much more substantially altered polypeptide.

A change to DNA therefore does not necessarily produce a large change in the protein.

DNA base sequencebase tripletsamino acid sequencepolypeptide

Exam Tip: Say that a mutation may alter the encoded amino acid sequence. Do not state that every DNA mutation must change the polypeptide.

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