Introduction
Amylase is an enzyme that catalyses the breakdown of starch into sugars. Amylases are found in almost all plants, animals and microorganisms. Large amounts of amylase occur in germinating cereals, and in the pancreas and saliva of higher animals.
Aim
The aim of this experiment is to find out the rate of reaction between amylase and starch in a range of different reaction temperatures.
Hypothesis
As the reaction temperature of amylase solution and starch solution increase, the reaction rate of amylase and starch will increase. After reach the optimal temperature of amylase, the reaction rate of amylase and starch will rapidly decrease.
The lock and key model explains my hypothesis. Most enzymes are very specific for a certain substrate, the active site on the enzyme molecule forms a "keyhole" into which the substrate fits like a key, the substrate molecule is then broken up into many smaller pieces. The higher reaction temperature, the more kinetic energy the substrate molecules will have. It means that the molecules can move faster and have a greater chance to collide and react. However, if the reaction temperature is too high, enzyme may become denatured. Denaturation is a structural change in a protein that alters its three-dimensional shape and causes the loss of its biological properties1. As the temperature rises the amount of active enzyme progressively decreases, and the rate of reaction is slowed. So there should be an optimal temperature for each enzyme.
Research Question
How does a range of different reaction temperature (0°C, room temperature during the experiment, 40°C, 60°C, 80°C) effect on the rate of reaction between amylase and starch?
Variables
Dependent variables: the required time for the disappearance of blue-black color (color of Iodine solution mix with starch solution ).
Independent variables: reaction temperature (0°C, room
References: 1. "Biology for IB Diploma" by C.J.Clegg, published by Hodder Education. 2007. Bibliography Ramasubbu, N.; Paloth, V.; Luo, Y.; Brayer, G. D.; Levine, M. J. (1996). "Structure of Human Salivary α-Amylase at 1.6 Å Resolution: Implications for its Role in the Oral Cavity". Campbell, Neil, J. Reece, and L. Mitchell. Biology 5th Edition. Menlo Park, CA. Benjamin/Cummings, 1999.