Metabolic Processes Interrelated with the Law of Entropy

Metabolism is a combination of two reactions or more notably known as a coupled reaction. It is comprised of an anabolic reaction and a catabolic reaction. The process of synthesizing  macromolecules where cell growth and development takes place is known as the anabolic reaction. If we look at an energy graph for an anabolic reaction, energy is needed in order for the reactants to become products. Therefore, anabolic reactions are endergonic and require energy. On the other hand, the process of breaking down large molecules into smaller molecules is known as the catabolic reaction. This time when we look at an energy graph for a catabolic reaction, energy is released rather than required when the reactants form into products. This results in an exergonic reaction and a release of energy. The graphs shown below compare the two types of reactions where the change in G is the energy required or released. 
One must know that since exergonic reactions are spontaneous, they drive the endergonic reaction causing the overall free energy change to be negative which obeys the second law of thermodynamics also known as the law of entropy because the overall disorder is increased. Here is an example of what happens with our bodies to further explain this concept of an increase in entropy. When we put food in our mouths, we use energy to make the food and eat it which can replicate the endergonic reaction or the anabolic reaction. On the other hand, when we excrete waste like human feces, we release energy in the form of heat. This replicates the exergonic reaction or the catabolic reaction. The difference is that excreting waste happens naturally whereas eating food requires us to do it. So even though we try to create order by feeding ourselves, disorder or chaos still increases because pooping occurs naturally and ultimately we must go through the entire process again.

 

The Three Thermodynamic-keteers :O

Everything in nature must obey what the Three Thermodynamic-keteers say.

The First Musketeer-Conserving Mass and Energy


The first musketeer named Energio says that, "Energy can neither be created nor destroyed."



With that being said, if Energio eats lettuce, the calories from the lettuce is used to provide energy for Energio so that he can fight off the bad guys. So no new energy was created for Energio to fight. He simply got it from the calories of the lettuce. 


Similarly, the energy from the lettuce was not lost because Energio's body transformed it into another form of energy in order for him to fight. It could have been simply turned into a form of sound energy from his yells during the fight. As you can see, energy was neither created for Energio nor destroyed for the lettuce, but was rather transformed from calories into sound energy. 



The Second Musketeer-The Law of Entropy


The second musketeer named Chaotic claims that, "All disorder, chaos or randomness creates more disorder, chaos or randomness."


For example, the following changes in state....

solid--> liquid

solid--> gas

liquid--> gas

.... will always exhibit the second law of entropy because as you can see from the diagram on the left, the organization from the solid phase to the gas phase gets more random, disordered, and chaotic and ultimately increases entropy.


Chaotic describes that entropy happens in our bodies when we take in the energy from the lettuce (the solid sugars aka glucose) and we breath the oxygen gas in the air which turns into carbon dioxide gas and liquid water. The reaction that has happened in our body called cellular respiration goes from a solid + a gas --> a liquid + a gas. So wouldn't you agree that entropy has increased?

The Third Musketeer-Absolute Zero


The third musketeer named Zero states that, "At absolute zero, all thermal molecular motion is removed."


This is Zero's reasoning: He claims that he is so hot that when everybody sees him, they offer their heat to him so that he can become even hotter. Without the heat, the people die and disappear, ceasing to exist. 


Having all thermal molecular motion be removed means that our bodies will be at a very low temperature and will be nonexistent, so enzymes that are part of metabolic processes cannot work.