Water is a polar molecule because a it does not have a charge. b it contains two hydrogen atoms for each oxygen atom. c different parts of the molecule have slightly different charges. d it has a charge.

The answer is telescope.

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.