Investigating the Effect of Pepsin on Egg Whites
Medora Choi, Lily Ge
Abstract: The purpose of this experiment was to investigate the effects of temperature and pH levels of pepsin on protein digestion. The independent variable was the pH level and the temperature. The dependant variable was the egg white The enzyme’s action at three temperatures was tested. The effectiveness of pepsin was observed at three temperatures: 6˚C (refrigerator temperature), 15˚C (room temperature), and 37˚C (human body temperature). Egg white was used as protein for the experiment held. This experiment lasted for 4 days. On the first day, a hardboiled egg was provided and was cut into 36 cubes using a scalpel. There were 12 test tubes, each of them containing different amounts of distilled water, pepsin, hydrochloric acid, and/or sodium bicarbonate. 3 cubes of egg white were put into one of the 12 different test tubes. Four test tubes were put in the refrigerator, another four were left at room temperature, and the last four were placed in the incubator. Over the next three days observations were recorded. Throughout the three days, the test tubes in the refrigerator and the test tubes left in the room temperature remained unchanged while the test tubes placed in the incubator dissolved. Overall, the investigation showed that the higher the temperature is, the faster the food is digested.
Introduction: The digestive system is composed of different organs which produces different enzymes. Enzymes are proteins which consists long chains of amino acids that are held together by peptide bonds. Enzymes are also very specific because each enzyme can break down one particular compound, which makes the process more efficient. Most of them can be found in the digestive tract. They perform an important function by controlling the metabolic process to convert nutrients to energy. However, the most vital function is that enzymes take part in the digestive system by breaking down food material into smaller molecules. One of the best known enzymes is found in the digestive tract called pepsin which breaks down proteins into amino acids. The process of breaking down protein is called protein breakdown, also known as protein catabolism. Protein breakdown is when protein is broken down into their constituent amino acids which are then absorbed by the blood capillaries and transported to the liver. The amino acids are then synthesized into proteins or stored as fat for energy. Therefore, in this investigation, we will explore the optimum temperature for the action of pepsin.
