An investigation into the action which trypsin has on casein in milk.

Authors Avatar

Biology Coursework: An investigation into the action

which trypsin has on casein in milk


  An enzyme is a substance that acts as a catalyst in living organisms, regulating the rate at which chemical reactions proceed without itself being altered in the process.

The biological processes that occur within all living organisms are chemical reactions, and enzymes regulate most. Without enzymes, many of these reactions would not take place at a perceptible rate. Enzymes catalyze all aspects of cell metabolism. This includes the digestion of food, in which large nutrient molecules (such as proteins, carbohydrates, and fats) are broken down into smaller molecules; the conservation and transformation of chemical energy; and the construction of cellular macromolecules from smaller precursors. Many inherited human diseases, such as albinism, result from a deficiency of a particular enzyme.

Enzymes also have valuable industrial and medical applications. The fermenting of wine, leavening of bread, curdling of cheese, and brewing of beer have been practiced from earliest times, but not until the 19th century were these reactions understood to be the result of the catalytic activity of enzymes. Since then, enzymes have assumed an increasing importance in industrial processes that involve organic chemical reactions. The uses of enzymes in medicine include killing disease-causing microorganisms, promoting wound healing, and diagnosing certain diseases.

Join now!


Our experiment involves seeing what affect an enzyme, called trypsin, has on a protein, called casein, in a milk solution. The first thing we must do is to put different concentrations of trypsin into milk solution, and see how long it takes for each solution to turn transparent. We will time how long it takes it each solution to go transparent. We will then use different pH buffer solutions, in order to change the pH of the reaction, and see how trypsin will react in each solution.

I predict that the reaction rates will be higher ...

This is a preview of the whole essay