Death+By+Design+Notes+BH

Programmed Cell--> cells are supposed to kill themselves once they are not useful anymore. Cancer cells bypass PCD continue to divide and make a tumor.

cell- ultimate unit of life. everything that is alive is either a cell or made up of cells.

Leeuwenhoek --> 1500's first microscope. He looked at an onion. Monks--> looked like the rooms monks live in

animal cells--> bubbles they don't have walls they look more like bubbles. They move around--> they can do everything animals can do.

they come together and form gourp and unities. THose unities are called animals and plants. the interactions create plants and animals. (community of cells)

much like people living in a big city. different roles in this community. Htey all have their own jobs and set of tasks. all of the cells have to get together at the proper state and time in order to form plants and animals.

one cell- any cells- they create organisms.

enormously long time to create living beings.

single cell animals do not interact with their neighbors. they have to know about each oher and talk to each other. --> they talk just like humans do. In general they send signals.

Cancer cells don't listen to signals. cells don't do anything unless they are signaled to do it. cells obey signals much like we do. (traffic signals, lights, signs, ect.)

gasses, protiens, small molecules,ect. --> move, grow, divide, or don't divide... any one cell is listening to hundred's of signals at any one time. --> they decide whehter to listen or not... all or none decisions..

for cells to stay alive they need somone to tell them to stay alive. If no one tells them to stay alive they kill themselves. during the course of an hour millions of cells withing you commint suicide.

PCD requires the cell to mke molecules in order to kill itself. These cells are not killed.. they are told to die.

cells starts PCD whe "told" to die..

kill--> engulf--> destroy..

for example--> webbed feet- cells are told to die between the fingers leave fingers. cell death sculpts them.

tad poles--> signaled by the thyroid hormone that effectively tells cells to die.. or provide new cells. smae thing with embryo--> 80 or 90 percent of the nerve cells originally created die.

when making an animal you must kill/destroy/remove.

humans=1000000000000 cells worm=959 cells

why ake a cell if you are going to tel it to die? probably b/c that cell had a purpose in an ancestor but not now.