dna mutations that can affect thebirdmanscience.weebly.com/.../5/...presentation_1.pdfnormal dna...

DNA mutations that can affect the resulting protein by changing ONE BASE.

Point Mutations

T H E F A T C A T A T E T H E R A T

T H E F I T C A T A T E T H E R A T

Substitution. Reading frame stays the same – no frameshift. Only on amino acid will change, maybe not… why?

T H E F A T C A T A T E T H E R A T

T H E F T C A T A T E T H E R A T

Deletion. Reading frame changes!! –frameshift happens. All amino acids after the deletion will be affected.

T H E F A T C A T A T E T H E R A T

T H E F I T O C A T A T E T H E R A T

Insertion. Reading frame changes!! –frameshift happens. All amino acids after the insertion will be affected.

Summary.

Point mutations only affect one base but can either have little (one amino acid) impact or serious impact (all downstream amino acids)

Mutations that impact large sections of DNA.

Chromosomal Mutations

Why are mutations

called “random”?

The overall error rate of DNA polymerase in the is 1 in 100,000,000 base pairs. Repair enzymes fix 99% of these errors and results in one mutation in every 10 billion base pairs that are replicated during the S-phase.

An alteration of the DNA sequence that results in an change (beneficial or deleterious) of the protein product that it codes for.

An agent that causes a mutation. Chemicals (bromine gas) and radiation (UV) are examples.