NH+Death+By+Design+Notes

PCD -programmed cell death -cell suicide -cancer cells bypass PCD -continue to divide and make a tumor -coordinated set of events -"neat" death -destroy evidence (eat the dead cell) Cells -10^13 cells in your body -Leeuwenhoek -microscope -looked at onion skins and found that they were made of squares and called them cells community of cells -different roles in the community of cells -started out as unicellular organisms and evolved into a multicellular organism -took 3 billion years -social interactions between unicellular organisms -cell communications -send signals to one another -cancer cells get the signal to die and don't listen -cells don't do anything unless signaled to do it -all cell behavior in an animal is coordinated with eachother -move, grow, divide!....or not -cells only divide when new cells are needed -how do we know -put a sell alone without any way to get signals and it won't do anything - a cell needs other cells to get signals to stay alive, otherwise it kills itself - PCD requires the cell to make molecules to kill itself -it participates in its own death -a cell starts PCD when told to die -when in the womb, we have webbed feet until the webbing cells get a signal to die and what is left is our fingers and toes -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