1. 12.4 Mutations

2. Complete the 2 tables on the first page of your handout. Try this without using your notes first and only refer to your notes on transcription and translation if you are struggling. From your tables and both translated sequences, what do you think a mutation is? Think About It!

3. What is a mutation? And what can a mutation do?  A mutation is a permanent change in the DNA sequence of a gene.  Mutations in a gene's DNA sequence can alter the amino acid sequence of the protein encoded by the gene.

4. Mutation Types Point mutations : single nucleotide base changes in a gene's DNA sequence. This type of mutation can change the gene's protein product in the following ways:

5. 3 Types of Point Mutations 1. Missense mutations 2. Nonsense mutations 3. Silent mutations  Ex’s:  Cystic Fibrosis  Neurofibromatosis  Sickle Cell Anemia  Tay-Sachs  Color Blindness

6. Missense Mutation Result in a single amino acid change within the protein.

7. Nonsense Mutation -Create a premature “stop signal" (or "stop" codon), causing the protein to be shortened.

8. Silent Mutation  Do not cause amino acid changes within the protein.

9. Frameshift Mutations  Change the grouping of nucleotide bases into codons.  This results in a shift of "reading frame" during protein translation.

10. Insertion Mutation Add a DNA Base

11. Deletion Mutation Remove a DNA Base

12. Lactose Tolerance Antibiotic Resistance HIV Immunity Malarial Resistance from Sickle Cell Anemia But… mutations can also be beneficial

13. Mutagens Carcinogens Radiation UV light Environmental Heavy metals Chemical exposure (VOC’s) Bacteria and Viruses Or they could be induced

14. The World Health Organization’s International Agency for Research on Cancer (IARC) announced that it has moved UV tanning beds to its highest cancer risk category -- "carcinogenic to humans." The use of tanning beds before age 30 is associated with a 75% increase in melanoma risk. Skin cancer occurs when errors (mutations) form the in the DNA of healthy skin cells. The mutations cause the cells to grow out of control and form a mass of cancer cells Skin Cancer

15. Lung Cancer Smoking causes 87% of all lung cancer cases. Smokers have approximately one chance in 10 of developing lung cancer over his/her lifetime.

16. Sickle Cell: http://www.dnalc.org/resources/3d/17-sickle-cell.htmlhttp://www.dnalc.org/resources/3d/17-sickle-cell.html Mutating virus: http://video.nationalgeographic.com/video/national- geographic-channel/shows/naked-science/ngc-deadly-mutation/http://video.nationalgeographic.com/video/national- geographic-channel/shows/naked-science/ngc-deadly-mutation/ Radiation leading to mutations and cancer: http://www.dnai.org/lesson/go/1738/1419 Addition and deletion mutations: http://highered.mcgraw- hill.com/sites/0072556781/student_view0/chapter11/animation_quiz_4.htmlhttp://highered.mcgraw- hill.com/sites/0072556781/student_view0/chapter11/animation_quiz_4.html Videos