So here you have a system, you have something -- and there’s plenty of that stuff in biology -- some substance giving an electron, and the electron tries to jump, and only when a molecule comes along that has the right vibration does the reaction happen, OK?
I tako dobijete sustav, imate nešto -- toga ima dosta u biologiji -- neka tvar koja daje elektron i elektron koji pokušava skočiti i jedino kada dođe molekula koja ima točnu vibraciju, dogodi se reakcija.