Enzyme Lab

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LABORATORY REPORT
(Click on the Save a Copy button on the panel above to save your report) Activity: Enzyme Activity
Predictions
1. Sucrase will have the greatest activity at
pH 6
2. Sucrase will have the greatest activity at
60 °C (140 °F)
3. Sucrase activity
decreases with increasing sucrose concentration.
Materials and Methods
Effect of pH on Enzyme Activity.
1. Dependent Variable.
amount of product (glucose and fructose) produced
2. Independent Variable.
pH
3. Controlled Variables.
temperature; amount of substrate (sucrose) present; sucrase + sucrose incubation time Effect of Temperature on Enzyme Activity.
1. Dependent Variable.
amount of product (glucose and fructose) produced
2. Independent Variable.
temperature
3. Controlled Variables.
pH; amount of substrate (sucrose) present; sucrase + sucrose incubation time Effect of Substrate Concentration on Enzyme Activity.
1. Dependent Variable.
amount of product (glucose and fructose) produced
2. Independent Variable.
amount of substrate (sucrose) present
3. Controlled Variables.
temperature; pH; sucrase + sucrose incubation time
1. Describe what is measured as an indicator of sucrase activity and why this is an indicator of sucrase activity. Amount of product (glucose and fructose) produced is what is being measured for this lab. This is an indicator of sucrase activity because the amount of product produced is a result of the expiriment itself. 2. Explain why denatured sucrase was used as a control.

Denatured sucrase was used as a control because activated sucrase would increase the activity. 3. Alkaline DNS denatures sucrase. Explain why it is important to denature the enzyme. It is important to denature the enzyme because leaving it active would increase the activity of the enzyme. Results

Table 1: Effect of pH on Sucrase Activity
Optical Density
ph 3 ph 4 ph 5 ph 6 ph 7 ph 8 ph 9
1 0.156 0.292 0.653 0.935 0.782 0.429 0.151
2 0.165 0.321 0.666 0.92 0.763 0.429 0.151
3 0.188 0.322 0.674 0.942 0.821 0.421 0.151
average 0.17 0.312 0.664 0.932 0.789 0.426 0.151
Effect of pH on Sucrase Activity
1. State the optimum pH for sucrase activity and how sucrase activity changes at more acidic and alkaline pH values. Glucose of sucrase is the highest at pH value 6. When acidic or basicsucrase activity becomes less active. Table 2: Effect of Temperature on Sucrase Activity

Optical Density
10 °C
(50 °F)
20 °C
(68 °F)
30 °C
(86 °F)
40 °C
(104 °F)
50 °C
(122 °F)
60 °C
(140 °F)
70 °C
(158 °F)
1 0.01 0.276 0.757 0.964 0.906 0.835 0.636
2 0.009 0.291 0.777 0.959 0.942 0.835 0.64
3 0.009 0.263 0.764 0.944 0.933 0.8 0.648
average 0.009 0.277 0.766 0.956 0.927 0.823 0.641
Effect of Temperature on Sucrase Activity
2. State the optimum temperature for sucrase activity and how sucrase activity changes at lower and higher temperatures. Optimum temperature for sucrase activity is 40 degrees C. Sucrase activity decreases and becomes denatured at lower and higher temperatures.

Table 3: Effect of Sucrose Concentration on Sucrase Activity Optical Density
35 g/L 30 g/L 25 g/L 20 g/L 15 g/L 10 g/L 5 g/L 0 g/L
1 0.991 1.015 0.942 0.892 0.83 0.777 0.524 0.002
2 0.993 0.998 0.944 0.898 0.83 0.753 0.507 0.003
3 0.97 1.004 0.948 0.899 0.856 0.756 0.53 0.002
average 0.985 1.006 0.945 0.896 0.839 0.762 0.52 0.002
Effect of Sucrose Concentration on Sucrase Activity
3. State how sucrase activity changes with increasing sucrose concentration. Sucrase activity increases with increasing sucrose concentrations. Discussion
1. Explain how pH and temperature affect enzyme activity.
Increasing temperature means the molecules gain more kinetic energy and move faster resulting in more chances of succesful collisions of enzymes and substrates forming enzyme-substrate molecules. Since pH is one of the factors for the denaturation of proteins, if an enzyme is submitted to a pH level under which it is denatured there will be no enzymatic activity. 2....
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