Mutations And its affect on Protein synthesis Application

Mutations - And its affect on Protein synthesis

Application Learning Outcome B 8 -2 It is expected that students will: - use examples to explain how mutations in DNA change the sequence of amino acids in a polypeptide chain and as result may lead to genetic disorders.

Definitions mutation: A change in the sequence of bases within the DNA

Types – Frameshift Mutation One or more nucleotides is inserted or deleted from the DNA Example: TAC GGT TAG, insert C into the 4 th spot: TAC CGG TTA G The original DNA coded for which amino acids? DNA: TAC GGT TAG m. RNA: AUG CCA AUC amino acids: methionine – proline - isoleucine The mutated DNA now codes for which amino acids? DNA: TAC CGG TTA G m. RNA: AUG GCC AAU C animo acids: methionine – alanine - asparagine

Types– Point Mutations a change in a single nucleotide within the sequence Example: TAC CCA, GAC replace 2 nd A with a C TAC CCC, GAC The original DNA coded for which amino acids? DNA TAC CCA, GAC m. RNA: AUG GGU CUG amino acids: methionine – glycine - leucine The mutated DNA now codes for which amino acids? DNA: TAC CCC, GAC m. RNA: AUG GGG CUG animo acids: methionine – glycine - leucine

Definitions - Gene Mutation What effect does changing the amino acids have on the protein product? Changes the shape. Since shape determines function, it alters how the protein will function.

Proteins: Shape determines Function!

Question - Gene Mutation Which has the potential for the most damage, frameshift mutations or point mutations? And why? Frameshift – all amino acids are affected after the addition or deletion

Application Learning Outcome B 8 - 1 It is expected that students will: - give examples of two environmental mutagens that can cause mutations in humans.

Definitions Mutagens Environmental influences that cause mutations Brainstorm a list Here are some examples: Radiaton: radioactive elements, ultraviolet (UV) light, X rays Organic chemicals: cigarette smoke, pesticides