LC=Death+by+Design

Death by Design Notes 1. Programmed Cell Death (PCD) - Cell Suicide - Cancer Cells bypass PCD: continue to divide and make a tumor 2. Cells are the unit of life - Leeuwenhock: first invented the microscope;studied cells in onions - Animal Cells: have no wall just a soap bubble - Community of Cells: Cancer is disobeying the rules; Different roles in this community - Unicellular organism: sexual interactions to reproduce - Multicellular organism: came much much later - Evolved to interactions: sexual interactions - Signals: They talk to one another 3. PCD and Death of Cells - Cancer cells don't listen to the signals to die - Cells don't do anything unless they are signaled to do so. - Move, Grow, Divide, Don't divide - Without any signals, cells kill themselves - One cell in a dish, dies. - PCD requires the cell to make molecules to kill itself. - Cell Starts PCD when "told" to die. - PCD: "neat" death: destroy all evidence - Webbed feet in the womb: cells in between die and others make fingers - PCD of neurons (80%) in developing fetus - Why make a cell if you are going to tell it to die? - Probably because that cell had a purpose in an ancestor but not now. - Humans have 10^13 cells - Worms have 959 cells