When I first started to learn the laws of thermodynamics and the laws of energy I wasn’t able to fully comprehend just what the importance was of this topic. Topics like work, entropy, enthalpy, or even energy were just formulas to know. I now have started to unravel the bigger picture.
All life-forms exist to do work. Anything living organism is alive because it has the potential to do work. Work is only accomplished by making use of energy. The single most important molecule in all forms of biological energy is adenosine triphosphate (ATP). When I hold an object in my hand above the ground I am performing work to displace the object away from the ground. It is displaced away from the ground because if I were to let go gravity would pull the object towards the ground. By holding the object in my hand I have provided it with a form of energy, potential energy. If I let the object drop it will fall to the ground and convert the potential energy to kinetic energy. When the object stops moving and rests it exists at equilibrium on the ground. I can pick up the object again and convert my own ATP to the potential energy. So why is it life-forms have energy to perform work?
ATP is the byproduct of multiple steps in the metabolism of carbohydrates and fats. The carbohydrates and fats are ultimately drawn from plant sources. Plants synthesize their complex sugars via photosynthesis where the energy from the sun converts CO2 to glucose. In short the energy from the sun provides the energy for every form of life on our planet. The second law of thermodynamics states the universe is always driven towards maximum entropy or maximum randomness. However sometimes order can be created and in our universe this occurs on very large rocks around a much larger heat providing star. Essentially, our sun has provided energy for all Earth’s living organisms do any of work they potentially do.
Chemical reactions convert reactions to products ( A –> B) and every reactions exists with an equilibrium state. That is the ratio of products, B, to the reactants, A, if the reaction was given infinite time to complete. When the product very likely to form from the reactant, such that at equilibrium there would always be a large ratio of B:A then the reaction is said to be favorable. Living organisms make the most out of these favorable reactions because they keep the reaction held at a steady-state. In biology steady-state is a term that describes the constant influx of reactants to hold a chemical reaction away from its equilibrium state. When a very favorable reaction occurs there is a net release of free energy and life-forms, all organisms on our planet utilize this free energy to do work