IB Biology HL IA – Protein Digestion (using eggs and trypsin)

Research Question

What is the effect of pH in the enzyme activity of trypsin in the digestion of protein (egg albumin) by measuring the mass changes occurred in solutions with pH buffer of 2, 4, 6, 8, 10, and with and without trypsin, and through light absorbance of the solutions?

Background Information

Trypsin is a protease enzyme that digests protein in the small intestine. It is produced in the pancreas from an inactive form, trypsinogen. Trypsinogen travels through the bile duct and converts to active trypsin as it enters the small intestine. Trypsin is also responsible for repairing tissues such as bones, muscles, cartilage, skin, and blood. Moreover, it is also able to help in injury recovery through the combination with chymotrypsin (Healthline).

Denaturation is when a structural change occurs in a protein causing a loss of its biological properties. Since the formation and folding of a protein determine its properties, an alteration in its tertiary structure will cause the loss. The process of denaturation occurs in two conditions – temperature and pH. The alteration of the pH conditions will change the charge of the protein, and eventually the solubility and shape (Bioninja). This is shown in the image below (Figure 1). All proteins have an optimum pH where it functions best in. The optimum pH of trypsin is 7.8~8.7. (Chem.libretexts)