How Does Salivary Amylase Concentration Affect The Rate Of Reaction

Saliva collected at the beginning of experiment was found to have a pH value of 7(neutral) , as expected since the normal pH of saliva is 6 to 7 (Humphrey and Williamson, 2001). When testing the enzymatic action of saliva, we observed at the end of the experiment, that a yellow-red precipitate formed which indicated that sugars were present. The reason that sugars were found and not starch, is because saliva contains an enzyme known as salivary amylase which catalyses the breakdown of starch to produce sugars such as maltose (Sherwood, 2013). When testing the effect of the salivary amylase concentration, we observed that the solution containing the most saliva (3ml), become colourless faster than the solution which contained the least saliva (1ml). This proves that an increase in enzyme concentration (increase in saliva), will cause an increase in the reaction rate (Bennett and Frieden, 1969).
From cold water to room temperature, the time decreased. From room temperature to 37*C, the time continued to decrease. As the temperature continued to rise to approximately 50*C, the time increased which indicated a decrease in reaction rate. These results were expected since according to Bennett and Frieden (1969) the rate of reaction increases as temperature increases. However, the rate of reaction will increase up to a maximum temperature, and will then decrease as the temperature continues to increase. This is because enzymes perform at their specific optimum temperatures, and further increases in temperature lead to denaturation and loss of enzyme activity. Since the optimum temperature of salivary amylase is between 32*C and 37*C (Sherwood, 2013), an increase of temperature above this will result in a loss of enzyme activity (Bennett and Frieden,