1. Warm up 11/21 What are 3 differences between DNA & RNA? What is a codon? What is the Start Codon (or amino acid)? What is the final product of translation? Quiz ◦Moved to Friday Start of Class Exam: Tuesday Nov. 26 ◦Intervention Today 2:45-3:30 pm & Friday 6:50- 7:35 am 1

2. Notes: Mutation Preview 2

3. Errors in Replication ● Replication is extremely accurate, 1 error occurs for every billion nucleotides!!! ~equivalent to typing a book 1000 times and leaving only one error ● This is possible because proofreading enzymes follow the polymerase checking for errors ● Mutation = a change in the nucleotide sequence of DNA ● Some mutations are silent, others alter a gene’s function or may halt cell functions Cancer: Mutation that has lead to uncontrolled cell reproduction. 3

4. Mutations: Some mutations affect a single gene, while others affect an entire chromosome. A mutation is a change in an organism’s DNA. Many kinds of mutations can occur, especially during replication. Ex/ A point mutation substitutes one nucleotide for another. mutated base 4

5. Types of Mutations Point Mutation ◦Substitution: One Nucleotide gets mixed up for another. ◦Most of the time this is OK Frameshift Mutation ◦Insertion: A nucleotide is inserted in the sequence. ◦Deletion: A nucleotide is deleted from the sequence ◦This can be bad because every codon after the frameshift is misread. 5

6. 6

7. What does the following say? The quckr edf oxj umpedo vert hel azyb rownd og. The qucck red fox jumped over the lazy brown dog. The quick red fox jumped over the lazy brown dog. 7

8. Mutations may or may not affect phenotype. Some gene mutations change protein ◦A mutation may cause a premature stop codon. ◦A mutation may change protein shape or the active site. ◦A mutation may change gene regulation & be given to offspring. blockage no blockage 8

9. Classwork: ◦IT’S ALL IN THE RECIPE HW: ◦DNA Book  Pages 5-6 Due Friday ◦Study guide (due Monday) Quiz ◦Moved to Friday Start of Class Exam: Tuesday Nov. 26 ◦Intervention Thursday 2:45-3:30 pm & Friday 6:50- 7:35 am 9

10. Extra Credit 5 points of Lab Extra Credit: ◦Central Dogma of Molecular Biology Lab ◦Due on Tuesday ◦Lab Manual p 43-46 10