Directionality of Chemical Reaction and Spontaneity of Biological Process in the Context of Entropy

Abstract

Chemical and biochemical reactions are carried out either to generate energy or to produce useful macromolecules. Entropy is a well-applied concept in many fields, including physics, chemistry, biology, and medicine. Various perspectives have been used to describe the concept, creating confusion and misconceptions. In chemical and biochemical reactions, entropy plays a significant role in the directionality and spontaneity of the reactions. Potential energy can be used to better understand the concept of entropy. Potential energy represents order, while entropy represents disorder; therefore, they are inversely proportional and intimately linked. Molecules with high potential usually have rich sets of functions and information, which is due to the enrichment of their constitutions, configurations, and conformations. In molecules with low potential, there are greater vibrational, rotational, and translational motions associated with decreased order in their constitution, configuration, and conformation. Distribution of electronic charge changes in macromolecules over time, increasing the rotation of side-chain residues and thus increasing entropy and affecting potential in terms of structure, function, and information. Entropy can thus be defined as a state of spontaneous change, bound to time and constantly increasing, which causes structural changes in the form of constitution, configuration, and conformation, and functional changes in the form of the ability to do work as well as informational changes in the form of the transmission of commands.