The Affect of pH on Sucrase

The Affect of pH on Sucrase

• 171.15g of Sucrose
• One Cucumber
• 500 mL Beaker
• Electronic Balance
• 16 Glucose Test Strips
• Three 200mL beakers
• Pestle and Mortar
• Three Stirring Rods
• Stopwatch
• 100mL Graduated Cylinder
• Scalpel
• Three 10mL Graduated Cylinders
• 500mL Distilled Water

• Mash up the cucumber in the pestle and mortar to get the juice
• Measure 5mL of the cucumber juice and put it into a 200mL beaker
• Measure 500mL of distilled water and put it in a different beaker
• Mass out 171.15g of sucrose
• Dissolve the sucrose in the distilled water
• Mix the cucumber juice and 100mL of sucrose solution in a beaker
• In 2 other beakers have the same measurements of sucrose and cucumber
• Put a 3pH buffer in one of the beakers
• In another beaker put a 10pH buffer in
• Mix both solutions with a stirring rod
• Test the glucose levels every two minutes ending on ten minutes

Independent Variable: Concentration of sucrose

Dependent Variable: Amount of glucose produced

Control Group: pH of 7

Experimental Group: Acidic and basic solutions

Constant Factors: Molarity, Temperature, and amount of cucumber

Introduction

Discussion

Research Question

Will sucrase break sucrose down into glucose and fructose?

Background

By: Mia, Jonas, and Kayla

• Catylase decomposes hydrogen peroxide into water and oxygen (Goodsell, 2004, n.p.)
• Different cells use different forms of catylase (Goodsell, 2004, n.p.)
• Catylase can get rid of millions of hydrogen peroxide ions in a single second (Goodsell, 2004, n.p.)
• Sucrose Formula- C H O (PubChem, 2004)
• Sucrose molecular weight 342.30 (PubChem, 2004)
• Sucrase breaks sucrose into glucose (Zatkoff, 2005)
• Best pH is 2 (Zatkoff, 2005)
• Best temperature is 45 F (Zatkoff, 2005)
• Cucumber, potatoes, and sugarcane contain sucrase ("Types of enzymes and their," 2011)

Results

• Enzymes increase reaction rate of certain reactions (Campbell et al., 2008, p. 78)
• Enzymes are not consumed in the reaction (Campbell et al., 2008, p. 78)
• Most enzymes are proteins (Campbell et al., 2008, p. 78)
• Each enzyme has a most effective temperature (Campbell et al., 2008, p. 155)
• Each enzyme has a most effective pH (Campbell et al., 2008, p. 155)

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11

12

Control:

• started at glucose level zero
• stayed consistent at glucose level 100

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Conclusion

Hypothesis not supported

• data inconclusive
• no change after 2 minute mark
• acid test had lowest values

Limitations

• few glucose test strips
• small time frame
• improvised source of sucrase

Unexpected Results

• little change after 2 minute mark
• sucrase decreased
• unexplainable

Connection

• shows prevalence of enzymes

Evaluation

Confidence

• moderate
• cons
• unexplainable decrease in acid test
• results contradict previous tests
• pros
• previous tested used different enzyme source

Error

• source of enzyme may not be ideal
• human error

Refinement

• test different sources of sucrase
• pH values equidistant from neutral
• longer testing period
• test pH after the experiment

Future Experiments

• test different sources of sucrase
• test temperature affect on ideal pH
• test pH value at which sucrase is denatured
• test different pH values

Hypothesis

Acidic solution:

• started at glucose level zero
• in minutes 2 through 6 the glucose level raised to glucose level 100
• at 8 to 10 minutes, it went back down to glucose level zero

If the pH decreases then the amount of glucose present will increase.

Basic solution:

• started at glucose level zero
• stayed consistent at glucose level 100

Materials and Methods

Qualitative data:

• the sugar was dissolved most not all of the way

Procedure

Materials

Quantitative data:

• control and glucose stayed at glucose level 100
• acidic solution decreased to 0 at 8 -10 minutes

References

Graph

Data Table

• Campbell, N. A., Reece, J. B., Urry, L. A., Cain, M. L., Wasserman, S. A., Minorsky, P. V., & Jackson, R. B. (2008). AP edition biology (8th ed.) (B. Wilbur, Ed.). San Francisco, CA: Pearson Benjamin Cummings.
• Goodsell, D. (2004). Catalase. In Protein data bank. http://dx.doi.org/10.2210/rcsb_pdb/mom_2004_9
• PubChem. (2004, September 16). Sucrose - compound summary [Fact sheet]. Retrieved from http://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=5988
• Types of enzymes and their sources. (2011, September 10). Retrieved October 31, 2013, from http://benjimester.hubpages.com/hub/Types-of-Enzymes-and-Their-Sources
• Zatkoff, J. (2005, October 25). Enzyme analysis of sucrase for optimum temperature, pH, and consentration of sucrose. Retrieved October 30, 2013, from Jcorp website: https://www.msu.edu/~zatkoffj/rd/sucrose.html

There was minimal change in the control and basic solutions. The acidic solution increased to glucose level 100 then at 8 and 10 minutes the glucose level decreased to zero again.

Variables and Groups

Set-Up

This graph shows the control and basic solutions over lapping because they both have the same results. Then it shows the acidic solution decreasing gradually between the 6 and 8 minute marks.