Gene Mutations

Gene Mutations (Review) We learned about three types of gene mutations earlier in the unit: insertion – adds a nucleotide into the DNA deletion – removes a nucleotide from the DNA substitution – replaces a nucleotide with a different nucleotide. We also mentioned that insertion and deletion are known as frameshift mutations…..

Frameshift Mutations If we think about DNA as a code, a “frame” within that code would be _?__ nucleotides, which codes for a single amino acid. So adding or removing a nucleotide from the code, affects every single frame/amino acid from that point on.

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Substitution Mutations A substitution mutation can also be thought of as a POINT mutation because it only affects the single point of DNA where it occurs. Substitution mutations can have several different effects on DNA.

Substitution Mutations Missense mutations – When the nucleotide that is changed causes a different amino acid to show up in the protein.

Substitution Mutations Silent mutations – When the nucleotide that is changed doesn’t change the amino acid in the protein.

Substitution Mutations Nonsense mutations – When the nucleotide changes into a stop codon so the protein isn’t fully produced.