- And its affect on Protein synthesis Mutations - And its affect on Protein synthesis
Application Learning Outcome B8 -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 4th spot: TAC CGG TTA G The original DNA coded for which amino acids? DNA: TAC GGT TAG mRNA: AUG CCA AUC amino acids: methionine – proline - isoleucine The mutated DNA now codes for which amino acids? DNA: TAC CGG TTA G mRNA: 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 2nd A with a C TAC CCC,GAC The original DNA coded for which amino acids? DNA TAC CCA,GAC mRNA: AUG GGU CUG amino acids: methionine – glycine - leucine The mutated DNA now codes for which amino acids? DNA: TAC CCC,GAC mRNA: 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 B8 - 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