Death+by+Design+-+Rachel

= Video Notes September 7, 2007 =

Programmed Cell Death (PCD)

Cell suicide Cancer cells bypass PCD and continue to divide and make a tumor

Cell

Leevwenhoek After looking at plant, named the inside "cell"

Animal cells not like plant which are more brick like

Community of cells Different roles in this community of cell Cancer cells do not obey the rules of the community

multicellular communities came much much later (during evolution) at the beginning of times only uni-celluar organisms

How do cells communicate with each other? Cancer cells don't "listen" to signals.

Cells do not do anything without signals.

All the cells are moving thus speaking to one other through signals - the body signals to each cell whether to move, grow, divide, or don't divide.

For cells to stay alive they need signals to tell them to surivive. ex. if you seperate a singal cell into a test dish, it will be paralyzed (won't move) and will kill itself

PCD requires the cell to make molecules to kill itself it participates in its own death

Cell starts PCD when "told" to die

PCD "neat" death destroy evidence (eat the dead cell)

webbed feet - cells of web part are dead

PCD of neurons (80%) in developing fetus

analogy: when making an animal you have to kill/destroy/remove the scaffolding

humans = 10^13 cells worm = 959 cells

why make a cell if you are going to tell it to die? probably because that cell had a purpose in an ancestor