Lab Report for Lab 6









Biology 101









October 16, 2003




Introduction







Background Information: Enzymes are proteins which act as catalysts which speed up the chemical reactions. Substrates are the reactants that yield products by the means of enzymes. As long as the temperature pH and concentration are held together or in right amounts, enzymatic activity will carry on by giving off energy as heat. Extereme pHs [Low(acidic) and high(basic)], high temperature, and high concentration will denature the enzyme (amylase) giving no products. Enzymes sit in a substrate that is called the active site. Enzyme will sit on the active site to speed up the reaction process to yield more products. When enzymes are affected by high temperature, high pH and high concentration, it will denature the enzyme or kill it. This will not speed up the chemical reaction process. Enzyme must have optimal temperature, optimal pH and concentration to yield more products.





Purpose: The purpose behind this experiment is to use less concentration, extereme pH, and low temperature enzyme to yield more products. In the first experiment Effect of Enzyme concentration on enzyme activity we tested the presence or absence of starch as an indication that amylase has acted. Lugol\'s stain is added to test the presence of starch. In the second experiment Effect of pH on Enzyme activity the purpose was to see how constant concentration of Enzyme and different pH react with each other. Finally, in the third experiment Effect of temperature on Enzyme activity the purpose was to see if at higher temperature the enzyme will denature.







Hypothesis: High temperature and pH will denature the enzyme (amylase) will yield less products. Amylast will work best with pH of 7 or above because it likes basic environment. If amylase is boiled, it will denature the enzyme yielding less products. High concentration of enzyme will increase the enzyme reaction rate.







2a. Equipment Used:




2b. Collection of Data:


Test Tube Number:


Amount of Amylast


Amount of Water


Concentration %


1


4 mL


0 mL


100%


6


2 mL


2 mL


50%


7


2 mL [ ] of TT#6


2 mL


33%


8


2 mL [ ] of TT # 7


2 mL


25%








Buffer


5 min.


10 min.


15 min.


20 min.


pH 2


+ +


+ +


+ +


+ +


pH 7


+ + +


+ + +


+ + +


+ + +


pH 12


+ + +


+ + +


+ + +


+ + +








Enzyme


0 min.


5 min.


10 min.


Unheated


+


+


+


Heated


+ + +


+ + +


+ + +







According to the data one can conclude that by decreasing the pH and increasing the temperature, the enzyme becomes denatured. It does not speed up a chemical reaction anymore yielding less products. More products will not form quickly if any of these variables change. If temperature is increased or if the pH level is increased to more acidic conditions, or if the [ ] level increases, the enzyme does not function on the active site of the substrate and will break apart which eventually results in denaturization. If you decreased the amount of enzyme and changed one of the variables it will still denature the enzyme. Enzyme must be in its specific environmental condition or active reaction condition which means that [ ], pH, and temperature but be held constant in order for enzyme to work on substrate. If all these variables are constant then the enzyme will speed up the chemical reactions with no problem. In experiment two we see that amylase like the basic pH. It works better in basic conditions than in acidic conditions. Amylase works better in basic solution instead of acid solutions. Different enzymes have different pH requirements to yield more products. In our case pH of 7.0 or higher yield better products. If we put the amylase in acidic solution, the solution will denature the amylase. But basic solutions give you better speed of reaction (rate of reaction). Basic pH works best with amylase than acidic. Acidic pH denatures the amylase.


Description of the results: In the first experiment we the results we have obtained shows that enzyme concentration affects the rate of the reaction. In optimal conditions, if you double the concentration of enzyme, you should double the speed at which the reaction occurs. In experiment two we saw that amylase will work best with pH of 7 or above because it likes basic environment. Finally, in the last experiment we found that high temperature