Why is Thomas Jefferson well known

Thomas Jefferson is well known because he was an American Founding father. He was also the third president of the United States of America and the principle author of the Declaration of Independence.

Mitochondria produce atp, a high energy compound. atp is used for all sorts of enzyme-mediated reactions, such as making proteins/nucleotides/etc, certain compounds cross the cell membrane, muscles move, etc.  without this source of energy, a cell will die. it will not be able to repair itself, defend against pathogens, etc.