Research: Trypsin. Enzymes are proteins that speed up the rate of reaction in living things without being changed themselves.

Research: Trypsin.

Enzymes are proteins that speed up the rate of reaction in living things without being changed themselves. They are composed of polymers of amino acids and are biological catalysts.

They speed up reactions by a process called the induced fit hypothesis. Originally it was believed that the ‘lock and key’ hypothesis was how the enzymes work, but this is now believed to be incorrect because the enzymes can change shape so that the substrate (the thing that is broken up) can fit into the active site of the enzyme, which is why it is called the induced fit hypothesis. The lock and key hypothesis suggests that the enzymes are the correct shapes without having to change for the substrate to fit in, which they often are not. The substrate enters the enzyme and is digested in the active site of the enzyme.

Extracts from the Columbia Encyclopaedia.

Enzyme that acts to degrade protein; it is often referred to as a proteolytic enzyme, or proteinase. Trypsin is one of the three principal digestive proteases, the other two being pepsin and chymotrypsin. In the digestive process, Trypsin acts with the other proteases to break down dietary protein molecules to their component peptides and amino acids. Trypsin continues the process of digestion (begun in the stomach) in the small intestine where a slightly alkaline environment (about pH 8) promotes its maximal enzymatic activity. Trypsin, produced in an inactive form by the pancreas, is remarkably similar in chemical composition and in structure to the other chief pancreatic proteinase, chymotrypsin. Both enzymes also appear to have similar mechanisms of action; residues of histidine and serine are found in the active sites of both. The chief difference between the two molecules seems to be in their specificity, that is, each is active only against the peptide bonds in protein molecules that have carboxyl groups donated by certain amino acids. For Trypsin these amino acids are arginine and lysine, for chymotrypsin they are tyrosine, phenylalanine, tryptophan, methionine, and leucine. Trypsin is the most discriminating of all the proteolytic enzymes in terms of the restricted number of chemical bonds that it will attack. Chemists have made good use of this fact interested in the determination of the amino acid sequence of proteins; Trypsin is widely employed as a reagent for the orderly and unambiguous cleavage of such molecules.

Factors that affect the activity of Trypsin.

This can alter the rate of reaction because if the pH is too high or too low for the enzyme, it will become denatured, where the structure of the enzyme is changed so that substrates will no longer be able to fit inside the enzyme and therefore will not be digested. Most enzymes work best at pH 7, although some enzymes in the stomach work best in very acidic conditions (pH 1 or 2). The enzyme in my investigation (Trypsin) works best between pH 7 and 8, because it works in the duodenum, which is slightly alkaline as pancreatic juice, is present in the duodenum, which is alkaline.

Temperature

Temperature can alter the rate of reaction because enzymes work best at 40°C and if the temperature is lower then the molecules will move slower and therefore there will be less collisions of enzymes with substrates and the rate of reaction will be slower. If the temperature is higher than 40°C then the enzymes may become denatured and they will not work properly, slowing down the rate of reaction or if the temperature is high enough to denature every ...