GENE MUTATIONS

1. GENE MUTATIONS 2011

2. MUTATION Change in the genetic material (DNA)

3. CAUSES OF MUTATIONS 1. Errors during DNA replication 2. Radiation and toxic chemicals 3. Viruses 4. Errors during formation of egg and sperm cells

4. IMPACT OF MUTATIONS DEPENDS ON THE CELL IN WHICH THEY OCCUR 1. Somatic Cell: may lead to cancer 2. Gamete Cell (sperm or egg) • Sterility (organism can’t reproduce) • Passed to offspring (birth defect)

5. GENE MUTATIONS Alters the DNA sequence of one gene on a chromosome • Affects the body’s ability to synthesize one type of protein. • All copies of that protein in the body may be defective.

6. TYPES OF GENE MUTATIONS • Point mutation • Frameshift mutation

7. POINT MUTATION Changes one base pair in the DNA sequence of a gene Ex: CAT TAG CAT GAG

8. OUTCOME OF POINT MUTATIONS 1. One amino acid is altered and the protein is defective.

9. Normal Mutated DNA AAA CCG ATT AAA TCG ATT mRNA UUU GGC UAA UUU AGC UAA A.A PHE GLY STOP PHE SER STOP

10. Alteration codes for the same amino acid and the protein is normal. (a benefit of the genetic code’s redundancy)

11. Normal Mutated DNA AAA CCG ATT AAA CCA ATT mRNA UUU GGC UAA UUU GGU UAA A.A PHE GLY STOP PHE GLY STOP

12. FRAMESHIFT MUTATION One or more base pairs are added or deleted from the DNA sequence of a gene Ex: CAT TAG CTT AG

13. IMPACT OF FRAMESHIFT MUTATIONS If the addition or deletion is NOT a multiple of three, all amino acids after the mutation are altered and the protein is defective.

14. Normal Mutated DNA AAA TGG CCG ATT AAA GGC CGA TT mRNA UUU ACC GGC UAA UUU CCG GCU AA A.A PHE THR GLY STOP PHE PRO ALA