Cause living things can not directly use most of matter which they found in nature. For example carbon, all organism use carbon in complex structure, that is in compound or macromolecule(glucose,fructose,amino acid). we can not directly earn ATP from C which we found in soil/other sources.
Bacteria has cytoplasm and ribosomes which are common with all cells and other living organisms
first left (up) trachea
first left (down) diaphragm
right (up) bronchiole
right (down) alveolus