The Kinetic Theory states that with increased temperature, molecules receive more energy, resulting in them speeding up their movement. If the starch and the catalase molecules are moving faster, they will collide more often. The collisions will also have more energy so more of them are successful. Therefore the rate of reaction increases. Preliminary Work. Enzymes are large globular molecules of which the vast majority is protein in nature. Enzymes have catalytic properties; in other words, they alter the rate of reaction without themselves undergoing a permanent change.
Most chemical reactions require an initial input of energy, called activation energy, to enable them to occur. Enzymes act as catalysts, reducing the need for activation energy and so allows reactions to take place more readily and at lower temperatures than would otherwise be necessary. This can be seen in the graphs. http://www. soton. ac. uk/~plf/ScI-Journal/vol1no2/v1n2k41. htm Prediction. I predict that the catylase will take less time to react with the starch as the temperature increases. However, above 40°C, I predict that the rate of reaction will decrease.
This is because the rising temperature affects the hydrogen and ionic bonds that determine the shape of the enzyme. As these bonds are broken the shape of the active site changes and the molecules of caseinogen can no longer occupy them. The catalase is now denatured and the rate of reaction will become zero. This is irreversible. http://encarta. msn. com/encnet/refpages/RefArticle. aspx? refid=761575875 If the temperature falls below 37°C, according to the Kinetic Theory the enzyme and substrate molecules will not be receiving as much energy, and therefore their movement will slow down.
This will reduce the number of collisions between the rennin and the caseinogen, and there is a higher probability that these collisions will be unsuccessful due to the lack of energy. Therefore the rate of reaction will reduce. The reaction of catalase with starch can be shown in graph form. Explanation of graph A is to do with collision theory; the ions need a lot of time to collide successfully. B is the optimum temperature; less time is needed to make the reaction take place. C is when the enzymes have denatured; they no longer fit together.