Literature Review of 'What the heck is an enzyme'

This article starts off by explaining what an enzyme is made of, namely protein or RNA, and their purpose, which is to facilitate the breaking or forming of chemical bonds. The energy barrier for a chemical reaction to occur is then introduced as a problem needing to be solved. This barrier is often very high, and can possibly take a very long time to overcome. Since many organisms that we know of do not have the time required or the ability to withstand the energy required to overcome this barrier, the enzyme is brought up as the solution to this problem.

The article begins the explanation of an enzyme by comparing it to a catalyst. It subsequently describes what a catalyst does, which is to lower the previously introduced energy barrier to a reaction. In an enzyme's case, it does this by using a small amount of energy to bring multiple molecules close together, which increases the likelihood of the reaction occurring to a near guarantee. The writer uses the analogy of two people in a closet vs. an auditorium, pointing out that an interaction between the two is much less likely to occur in the latter. In fact, the article makes use of several analogies to describe the function and purpose of an enzyme and to illustrate the concept of an energy barrier.

The first of these analogies starts very simple and explains the concept of energy. It uses the process of climbing a hill with a cliff at the top. Energy input is required to reach the top of the hill, but falling down the cliff would result in an equivalent energy output, but in a different form. This analogy nicely summarizes potential energy(Energy stored at the top of the hill), and kinetic energy(energy released when reaching the bottom of the cliff).

The next analogy used involves two people who are attracted to each other. To realize the potential of a possible relationship between these two there is a barrier in the form of social norms and anxiety that must be overcome. The possible relationship is the chemical reaction, and the social actions are the energy barrier. A third person can act as a catalyst to this relationship by introducing the two to each other. This third person is the enzyme.

The last analogy compares a pot of water over a fire in a fireplace to the ability of a cell to produce work using enzymes. After all, what good is a chemical reaction that doesn't produce useful work? Fire can only result in the presence of three ingredients, oxygen, fuel, and heat. Even if you have fuel and plenty of oxygen, these cannot be combined without overcoming an energy barrier. This is where the lighter comes in, or in a cell, the enzyme. Once the reaction occurs, it's released energy can be used to boil water, or in the cell's case travel distances or create proteins.

After fleshing out how an enzyme works using these analogies the article points out that enzymes are not one size fits all. Just like a fire makes use of a lighter or a rope is used to pull someone up a hill, there are different enzymes for different chemical reactions. This is mostly due to the fact that each enzyme is specifically shaped to accept only certain molecules. Due to the very specific shapes that are required for certain reactions, even a slight variation in the shape of these enzymes can result in unfortunate consequences. These misshapen enzymes often result from a mutation in a cell's DNA, which causes the enzyme to be synthesized incorrectly. One example given by the article is a person's inability to break down galactose because of the lack of a certain properly formed enzyme. This disorder is commonly known as lactose intolerance.

The article wraps up by praising the bacteria and its amazing ability to produce the enzymes it needs all on its own, as long as it is in its preferred environment. It ends by expressing the importance of enzymes in creating the building blocks for life.

Critique/Analysis

This topic was interesting to me for two reasons. The first is that enzymes fascinate me. The mechanisms by which they work seem almost too simple for how important their purpose is. As someone previously in engineering they are perfect parallels to so many concepts of technology and design.Catalysts are a figurative bridge that make so much possible, and without them the universe would be incredibly inactive. The second reason is that after reading several articles from this website I realized how succinct the author is and how well he breaks down topics into smaller and easier to understand concepts. I will gladly return when I need something on the website explained.

This article took multiple concepts taught in completely different fields and boiled them down to very easily digestible and relatable analogies. The author kept the topic very broad, not diving into anything too specific. While this made the article easy to understand, it also left out a few details that I think are very important to understanding enzymes. For instance, there was no mention of inhibitors or activators, which are key to a cell's ability to regulate enzyme activity, and seem like a fundamental part of a lot of enzyme's function.

Article cited

Brown, J. C. (1995). What the heck is an enzyme? Retrieved February 12, 2021. http://people.ku.edu/~igmdoc/enzyme.html