Molecular oxygen, O2, is essential for cellular respiration in all aerobic organisms. Oxygen is used as an electron acceptor in mitochondria to generate chemical energy. Take a look inside the cell to see these powerhouses of the cell, petite organelles mitochondria, click here.
1 : the action of perturbing : the state of being perturbed. 2 : a disturbance of motion, course, arrangement, or state of equilibrium; especially : a disturbance of the regular and usually elliptical course of motion of a celestial body that is produced by some force additional to that which causes its regular motion.
When you're perturbed, you're upset by something, and rattled enough by it to be thrown off your usual calmness into a state of confusion. When a planet is perturbed in astronomy, it is pulled in different directions by strong forces, which is a great metaphor for what happens to a person who is perturbed.