BCHM 3050 1st Edition Lecture 27 Outline of Last Lecture I. Blocking of Transcription or Translation by AntibioticsII. Epigenetic Regulation ExamplesIII. Regulation of Gene Expression in EukaryotesIV. Locus Control Region (LCR)V. RNA Processing-Alternative RNA SplicingVI. mRNA DegradationVII. OperonsVIII. DNA Binding ProteinsIX. Glucose vs. LactoseX. PROGXI. Activation of Lac OperonXII. Role of Catabolite Activating ProteinOutline of Current Lecture I. Mutationsa. Substitution b. FrameshifII. Chromosome-Level MutationsIII. Mechanisms for Point MutationsIV. Transition and Transversion MutationCurrent LectureI. Mutationsa. Humans replicate DNA once every 24 hoursThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.i. Top strand will make a proper DNA strand, while the bottom strand will make a DNA strand with a mutation, so half of the cell will have the mutationb. Substitution i. Point mutations – 5 types; 3 fall under the category of substitutionii. Substitution is substituting one base of a completely different baseiii. If it leads to a change in one amino acid à missense (i.e. sickle cell anemia – glutamic acid substituted for valine)iv. Mutation that doesn’t lead to a change in the amino acid à silent mutationv. Mutation introduces a stop codon, terminate the protein, worst of the 3 types à nonsensec. Frameshifi. When identifying a mutation, ignore the codons that come before the start codon (AUG) because they are not translated into amino acidsii. Insertion – type of frameshif, very bad, changes more than one amino acidiii. Deletion – type of frameshif, very bad, changes more than one amino acidd. Silence is the best, then missense; nonsense and frameshifs are very badII. Chromosome-Level Mutationsa. Inversions and translocations commonly occur in cancerb. Ex: down syndrome – 21st chromosome has an extrac. Ploidy generally happens at birth while point mutation occur due to the environmentIII. Mechanisms for Point Mutationsa. Base replacement – point mutation (analogues)b. Base alteration – epigenetic; add amino groups (chemical modifications)c. Base Damage – disrupt base-pairingIV. Transition and Transversion Mutationa. Transition mutation – 80% of mutation; replace purine with purine and pyrimidine with pyrimidineb. Ex: A replaced with Gc. Transversion – purine replaced with pyrimidine and pyrimidine replaced with purined. Ex: A replaced with
View Full Document
Unlocking...