How does our body “know” if an antigen marker on a cell or particle is "self" or "pathogenic”? Is the body always correct in this assessment? Give an example

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.

Hello there,before the 1940s, scientists believed that proteins, rather than dna, were the carriers of genetic material in the cell. why?   answer:   proteins are present within the nucleus