SBL100 Introductory Biology for Engineers PDF

SBL100 Introductory Biology for Engineers Archana Chugh Disclaimer:The slides in the lecture have been developed /used using information available from various relvant public domain sources...

SBL100 Introductory Biology for Engineers Archana Chugh Disclaimer:The slides in the lecture have been developed /used using information available from various relvant public domain sources purely for teaching purposes Aging and immortal cells  Aging ? (The Biology of Senescence)  Why do we get old ? What is aging ? Aging - Phenotypic changes that occur over time due to limiting processes Aging is a biological process and not a disease, per se Aging is a process that converts an optimally healthy, fit organism into a less healthy, less fit organism Are we programmed to die ?  Aging - features Aging = reduced functional tissue Aging = increased susceptibility to disease (age-related diseases) Aging = decreased resistance to stress (physical and mental) time-related deterioration of the physiological functions necessary for survival  Mortality in Aging and Non- aging Systems 3 3 non-aging system aging system Risk of death 2 Risk of Death 2 1 0 1 0 2 4 6 8 10 12 0 2 4 6 8 10 12 Age Age Example: radioactive decay Why do we age? Genes + Environment  Genes and Aging Genes determine species-specific life span Genes determine differences in aging among individuals within a species (differences in gene expression / polymorphisms)  Species-specific longevity genes Flies (Drosophila melanogaster) Mice Humans Turtles Life spans from 2 weeks to 200 years  AGING in MICE AND MEN (Cancer, osteoporosis, diabetes, etc.) MICE HUMANS Disease 18 Months 50 Years Fitness AGE (log) Mice and Humans are >90% genetically similar! Species-specific longevity genes What are the genes that determine why mice live