BIOL 1010U Lecture Notes - Lecture 15: Genetic Variation, Gene Pool, Phenotype
Document Summary
Textbook reference: chapter 15 in biology how life works (2nd ed. ) Emphysema risk: normal, 1at gene encodes enzyme that inhibits elastase function, smoking, smoking reduces a1at activity; increased elastin breakdown, mutant, homozygous for piz allele produce a1at with reduced activity. Individuals who never smoke can also develop emphysema how: mutation in the gene encoding alpha-1-antitrypsin (a1at, homozygous individuals produce. Individuals with the mutant gene and that smoke are produce a1at with reduced activity and therefore have reduced elastase inhibition. Individuals with the mutant gene and that smoke are far more susceptible to developing emphysema. 80% of all emphysema cases are associated with smoking: piz mutation. Piz/piz non smokers reduced a1at activity emphysema results (life expectancy 65 yrs) Piz/piz smokers increases severity and progression of disease (life expectancy 40 yrs) Neutral mutations: what is a neutral mutation, why do neutral mutations sometimes have an effect and sometimes not, e. g.
