ABSTRACT
Analogous physical situations are, respectively, a drop of ink localized to a small region in 1 L of H2O and the same amount of ink diluted in 1 L of solution. The spontaneous progression of events will be from the former to the latter because the latter is more probable. The change in the distribution of the drop of ink, from concentrated to dilute, is predicted by the Second Principle – the orderly arrangement spontaneously progresses to the disorderly arrangement. Cells are frequently known to accumulate dissolved substances in concentrations greater than those in the surroundings. In other words, entropy decreases in a local region; this process is called active transport. Hydrogen ions are pumped against a concentration gradient in a chloroplast thylakoid by using light energy as a free energy source. The hydrogen ions can then spontaneously rush out via passive diffusion, driving the endergonic synthesis of adenosine triphosphate.
