Which of the following objects can be seen from earth. because it produces its own light?

a weather satellite

mars

the moon

a distant star

You can elnimate the moon and mars  so the answer is a star

The answer is joseph is observing the colour of the reaction mixture to see whether proteins are present in the given solution.

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.