Enzyme Action

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Upon observation of the solutions and their pH for 1 hour in between 10-min intervals, it can be seen from the table (Table 3) that only test tube #1 turned neutral while the other two remained and became acidic. Only test tube #2 emulsified showing that fat digestion occurred while #1 and #3 failed. The negative result is due to the erroneous components of their solution which are not suitable for fat digestion unlike in test tube #2.

- Discussion

A lot of substances are secreted into the different segments of the digestive tract that facilitates in the breakdown of food. Among these substances, digestive substances are the ones that serve a greater purpose in digestion. They help in enhancing the rate of reactions by breaking the bonds between polymeric molecules to form monomeric ones. The presence of these enzymes plays a huge role and without them, chemical digestion would essentially not occur. Nevertheless, there are factors that can influence the activity of enzymes. Temperature and pH are amongst the factors that greatly affect enzyme action. Temperature affects the overall kinetic energy between molecules, thus, affecting the rate of reaction. The pH of the surrounding fluid can also alter the reactions. Enzymes have a particular pH where they have the proper conformation to have optimal catalytic activity. Digestive enzyme, however, have various pH levels among the different segments of the digestive tract giving the enzymes dissimilar maximal catalytic activity with according to pH compatibility at a different segment of the tract. Gastric enzymes like pepsin have a maximum catalytic activity at a very lower pH of the stomach. On the other hand, pancreatin works at alkaline level pH.

In the first part of the experiment (Table 1), digestion of carbohydrates was observed. Carbohydrates are the first ones to be digested in the digestive tracts since their chemical digestion starts in the mouth. The salivary enzyme in the mouth is amylase which breaks down polysaccharide amylose or starch into smaller units of disaccharide maltose. Starch can only be broken down at a suitable environment. If the temperature is too high or too low, the enzymatic activity will fail for it might denature in high temperature and not work efficiently in low temperature. Another factor to consider is pH. The pH in the mouth is neutral so it require a neutral environment to allow the catalytic activity happen otherwise it will fail.

The next class that are digested in the body are the proteins. Protein digestion takes place in the stomach where the gastric juices are produced. These juices contain a number of substances including hydrochloric acid (HCl) and the protease pepsin. With the presence of gastric juices, the pH in the stomach decreases which aids protein digestion. The low pH denatures the tertiary structures of ingested protein to make them easily digestible by enzymes and also, the low pH is required for activation of pepsin. The same mechanism was applied in the second part of the experiment (Table 2). Test tube with pepsin and HCl incubated at 37°C should have shown occurrence of digestion in the egg slice since it has the most compatible setting for enzymatic digestion. The other solutions failed due to the low temperature and high pH level.

Among the biomolecules in the body, lipids are the ones that are a bit challenging to digest chemically. The reason behind this is because lipids are hydrophobic and they tend to aggregate within the digestive tract decreasing the surface are and making it hard for water to make contact with the fat. Even more so, enzymes are also water soluble and can only interact with triglyceride molecules at their surface. So to make fat digestion successful, the aggregates of fat molecules must be broken into smaller pieces to allow fat-digesting enzyme Lipases make contact with their substrate. These lipases are present in the small intestine as to where fat digestion takes place. Bile from the liver and gall bladder are also important for they contain bile salts that enhance the digestion process. These salts serve as emulsification agents and help in breaking the large aggregates of fat that greatly increases the surface area over which lipases can come into contact. Upon contact, triglycerides are hydrolyzed into amphipathic free fatty acids and monoglycerides, both of which can be absorbed by the intestinal epithelium. Eventually, pH will decrease due to the liberation of free fatty acids.

Essentially, digestion of food cannot take place without the presence of the digestive enzymes which heightens the reactions needed for successful digestive processes.

- Practical Applications

Enzymes are used in a wide variety of fields. In food industry, enzymes are used in fermentation where compound rich energy is broken down into simpler substances. It also helps in breaking down large organic molecules. The most common one is the conversion of sugars and starches to alcohol by enzymes in yeast. In the field of genetics, one important enzyme is the restriction enzyme which cuts DNA at specific sequences and used to map DNA fragments or genomes. These maps form a foundation for more innovative genetic analysis. Another enzyme that has a lot of potential application is cellulases. They are used in various industries like pulp and paper, textile, biofuel and agriculture.

- References

Boundless. “Enzymes Used in Industry.” Boundless Microbiology Boundless, 08 Nov. 2016. Retrieved 20 Feb. 2017 from https://www.boundless.com/microbiology/textbooks/boundless-microbiology-textbook/industrial-microbiology-17/microbial-products-in-the-health-industry-199/enzymes-used-in-industry-1004-5469/

Miller, S. B. (n.d.). Simple Enzyme Experiments. Retrieved February 19, 2017, from http://www.ableweb.org/volumes/vol-6/10-miller.pdf

Digestive Physiology. Retrieved February 19, 2017, from http://www.indiana.edu/~nimsmsf/P215/p215notes/LabManual/Lab12.pdf