Summary Of Gulp By Mary Roach

Mary Roach dives into the world of science and biology throughout the novel, Gulp, and explains it particularly in reference to the alimentary canal. She starts at the beginning with simply how eating works when it comes to taste preferences. Since humans tend to “taste” through their noses, the act of eating is actually more of an olfactory experience, surprisingly enough. Next, the food must travel past the saliva which carries digestive enzymes and kills proteins in order for the food to get to the stomach. The gastric acid within the stomach then breaks down the food and sends it to be filtered back out through the anus. Roach specifically talks about the aspects that are less well-known, however. The gastric acid within the stomach quickly

One example involves human evolution. When describing hydrogen sulfide as lethal, Mary Roach explains that this may be the reason as to why humans have evolved to be so sensitive to its smell. When humans smell something unpleasant, the instinct is to get away from the smell as quickly as possible. Roach claims that humans have evolved this way because unpleasant odors often indicate harm so over time humans have developed to try to get out of situations involving any displeasing odors. This connection to the classroom has enhanced my understanding of evolution because it is a modern example of how evolution currently affects us. I know that when I smell something unpleasant that I would do nearly anything to get rid of it and this makes sense to me knowing that this reflex likely came from our evolved species. Another example that relates to class is one of the many roles of enzymes in the body. The active ingredient in beans is an enzyme which breaks down specific complex carbohydrates that are found in beans. This enzyme is also in your colon due to the bacteria residing there. Since the small intestine cannot absorb the complex carbohydrates, they continue into the colon where they are broken down by bacteria and their enzymes which ultimately creates an abundance of hydrogen. Long story short, this is why people are gassy after eating beans. This process helped me to better understand what enzymes do and how they work in the body to break things down. They give a prime explanation for something as simple as why people get gassy after eating