What is the difference between a living organism and a chair? Well a chair can maintain its state of equilibrium without the need for any help from its environment. Living beings of the other hand need an input of material and energy to maintain this equilibrium. Without this input living organisms will have to shift to a highly disordered state of equilibrium, the maximum state of entropy is death.
To fight against the ever assailing force of entropy, living beings must eat food, who would have thought? Yes, Food and its glorious gustatory blessing! Whether it is whole foods or processed foods we need it regardless to subsist. We all know that it’s the sustenance for life but is there another way of viewing what food really is? I look at food as energy in a low entropy state. The energy bound within the food whatever dish it may be remains dormant in a relatively orderly state without too much entropy disordering it. Food is ,relatively to other things, easily prone to being disordered in many various ways but have a think of that common cause that disorders food? Eating! So then, when someone finally eats the food the entropic processes really kick in as soon as the food finally arrives in the stomach and progressing throughout the digestive track, especially through the small intestines, with which, along with being inundated with hydrochloric acids the food is further broken up by all the various types of digestive enzymes (lipase, protease etc.) all resulting in the food being broken down into smaller and smaller digestible portions, the molecules, which would be sugars (glucose), being made short work of so that absorption by the body is eligible, along with the indigestible portions destined to become waste rather than absorbed by the body.
Food is bundled as a specific energy type called chemical potential energy, energy waiting to be released just like the releasing of a stretched elastic band, but not just any energy but the energy to fuel the engines of life and its continuity into posterity. The energy upon consumption is then released or disordered being used for cellular respiration as this diagram illustrates.
Adenosine triphosphate (ATP) is popularly known as the energy currency of life, being the product of mitochondrial respiration, these molecules are used by our cells to supply processes in the cell that require energy, energy responsible for almost all activities that need energy in the cell are driven by the energy released from ATP. From the transportation of molecules and the contraction and relaxation of muscle cells to the maintaining of concentration gradients for nerve cells or neurons to function such as the sodium/potassium pumps embedded in nerve cell membranes.
‘This conversion from ATP to ADP is an extremely crucial reaction for the supplying of energy for life processes’ – http://hyperphysics.phy-astr.gsu.edu
So chemical energy from food is used to supply the entire organism with the means for existential continuity and to perform activities and actions. The energy from the food is used to maintain a constant body temperature (37c) producing at the same time excess heat which is radiated out from the body as wasted energy. This heat energy cannot be contained and harboured within the body but must, as thermodynamics dictates, be emitted from the body continuously. No matter what heat transfer process we are talking about here, the result is always the same; loss of heat from the body. Heat is always transferred when there is a difference in temperature. The heat loss from our bodies that radiates out into the environment or to the rest of the universe is infrared radiation which can be measured using Infrared thermography, parts of the body emitting more radiation than the other will be detected by this as a special camera is used which is sensitive to infrared radiation.
For actions, energy is expended to effect muscle relaxations and contractions to perform all the various activities in daily life. For that matter, mechanical waves or pressure waves which is sound, expends energy just hear the noise coming from the pub on Saturday night! All the actions of the human body whether maintaining homeostasis (balanced internal body environment), performing actions and producing sounds are conversions of chemical energy from nutrition into kinetic energy or motion which then is converted, partly, yet again into the form of wasted heat as the first law of thermodynamics states: heat cannot be created or destroyed. It can, however, be transferred from one location to another and converted to and from other forms of energy. Which would be from kinetic energy in this example.
We as living beings use the proteins derived from the food we eat to repair and maintain our tissues and organs our cells die all the time (yet we do not mourn them) or they become damaged which means cells need to be replaced and repaired if the structure they are apart of is to be maintained. As mentioned briefly, what I am getting at is that living beings are always fighting against the disorderly effects of entropy it is always restless! Maintaining and repairing are the attempts to keep the organism in an orderly state as much as possible by using energy to maintain said orderly state.
Tangentially, a naturalistic response to the meaning of life would be ‘life’s purpose is consumption and reproduction’ I view that as a valid epiphenomenon of something more fundamental, it’s the trunk but not the root. We at the standupphilosophers instead say ‘you are not required to do anything else other than to carry on living’ for consumption and reproduction are activities that are contingent on the condition that the living being is carrying on being alive!
And what else is responsible for a living being to ‘carry on living’ other than the continued reproduction of the cycle of cellular respiration? All animals are required to do this in order to exist, bodies create the sensations of hunger which drives them to obtain and disorder the ordered arrangement of food which, when consumed, is then changed into different morphologies altogether! Food and water turns into faeces and urine for example! This process ensures that you carry on living and simultaneously, as a by-product of respiration, you always will constantly release heat and waste from your body as further contributing factors that increases the overall entropy of the entire universe along with the stars and their fuel!