Amylase Experiment

... he enzyme 'tweaks' the substrate molecule, pulling it out of shape and making it split into product molecules. High temperatures make enzymes inactive: this is because they are proteins, which are damaged by temperatures above about 40OC. Most enzymes work best at a pH of about 7. This is also because they are proteins, which are damaged by very acidic or very alkaline conditions. Due to the enzyme's unique active site it can only convert one kind of substrate molecule into one kind of product. First of all the average time taken for the starch to be digested in each condition was calculated. Temperature(OC) 10 21 32 40 50 55 60 67 80&90 Average Time (min) 9.8 6.7 5.3 5.5 3.5 3.0 3.5 4.5 10 + pH 8 7 6 5 3 2 Average Time (min) 9.5 6.7 4.5 2.8 4.7 9.2 The results were then plotted on a graph (see Graphs 1 & 2) and the points joined together. From graph 1, I can see that as the temperature of the mixture increases, the time taken for the amylase to digest the starch decreases. This happens fastest at 55OC, however if the temperature continues to rise then the time taken for the amylase to digest the starch rapidly increases. By the time 80 OC is reached the amylase does not digest the starch. From graph 2, I can see that as the pH of the mixture increases, the time taken for the amylase to digest the starch decreases. This happens fastest at pH 5. At a higher pH level than pH 5 the time taken for the amylase to digest the starch increases. Amylase speeds up the breakdown of long chain starch molecules into smaller chains of maltose. Enzyme molecules have a very precise three-dimensional shape. This includes a 'dent', which is called the active site. I ...