Science 47

Enzymes are proteins that catalyze (speed up) chemical reactions. During these reactions, the enzymes are not altered, and are continually reused until the chemical reaction they are catalyzing reach a stable equilibrium.

The catalytic effect of enzymes is determined by several factors. Temperature, pH, concentration of enzyme and other factors can speed up or slow down the reaction.

A group of students investigated the effects of temperature and pH on amylase, an enzyme found in saliva that catalyzes the breakdown of starches.

Experiment 1

Starch can be broken down into glucose, a simple sugar. Glucose can be detected by using an indicator reagent that turns from blue to orange in the presence of glucose and heat.

The group of students combined starch, amylase and water of varying temperatures. After 3 minutes, the indicator reagent was added and the color was recorded in Table 1.

Experiment 2

The students combined starch and amylase, and then added various amounts of hydrochloric acidHCL. They then used the indicator reagent as in Experiment 1. The results are shown in Table 2.