The term entropy is one of those concepts with a wide variety of descriptions and interpretations that are used in textbooks and often confuse students and teachers (5). Following the concept of entropy, in various textbooks and articles, the concept is often described as a state of disorder, randomness, irregularity or uncertainty. In other interpretations, entropy is described as a form of energy, such as disperse or waste energy, released in the form of heat. Many looks at entropy as unused or waste energy, therefore it is often ignored and considered as energy with less value (6).
Before discussing the concept in detail, it is necessary to summarize the circumstances that could potentially lead to high entropy:
- Generally, entropy is increased when substance change in phase from solid to liquid or gas (7);
- Most of the spontaneous reactions are entropy-driven, particularly when the number of moles in the product is higher than the number of moles in the reactant (8);
- According to the second law of thermodynamic, any change in energy form, part of the energy is released or lost in the form of entropy (9);
- Entropy increases as molecules diffuse from a high concentration area to a low concentration area. The expansion of the universe is always accompanied by increased entropy (10);
- Entropy increases by increasing temperature and/or decreasing pressure (11).
In all cases, when entropy is increased, many settings have been changed; covalent and non-covalent bonds are broken, the hydrophobic effect is altered, the rigid and native structure is transformed and increased with irregularity, meanwhile, complexity, factuality, and sustainability are lost, water molecules are rearranged, the number of structures, conformations, rotations, microstates, and phases are increased, molecular movements became uncoordinated, random in all direction, therefore it is fair to say entropy creates a new state with the devastating high disorder (12). If micromolecules are involved in the disorder, their movement increases the probability of molecules to collide with each other, such collisions generate heat, ultimately raise the temperature of the closed system, increase the kinetic energy and cause the molecules to vibrate so fast and violently that the strong bonds become weaker and weak bonds are broken (13).
Entropy is often studied at variable temperature and/or pressure. To gain a deep insight into entropy, it is useful to study changes in phases, reactions, energy forms and diffusion at constant temperature and pressure. Most commonly, this state exists in living systems such as humans, where temperature and pressure remain approximately constant under none-disease conditions.
The human being is a very important biological system, complex but responsive to different states; strong, weak, happy, angry, young, old, healthy, sick. The strength and weakness of entropy are greatly influenced by changes in state, shape, chemical reaction and diffusion. These processes exist in the biological system and play an important role in determining the direction of the process, so it is likely that entropy plays a role in disease development and healing processes (4).
For a better understanding of the entropic role, it is important to define the energy sources and to identify the factors that could lead to the accumulation or depletion of the energy. In this context, energy sources that produce work can be simplified in one form, namely potential energy.
