Bio 181 - Enzyme Lab

Cristobal Ramos-Torres

BIO-181

2/23/2017

Rachel Pikstein  

Enzyme Lab

Introduction

        Enzymes are biological molecule that increases the rate of a chemical reaction (catalyst) without being consumed, usually as a protein. Through the experiments conducted, I will be able to describe the effects of different environmental conditions and temperature, understand what it means for an enzyme to be specific, be able to explain the varying concentrations, and demonstrate scientific thinking. As mentioned before, an enzyme is a catalyst which means it is a substance that increases the rate of a chemical reaction without being consumed. For an enzyme to denature means to unfold a protein’s quaternary, tertiary, and secondary structure, rendering the molecule unable to function.

Objectives

• Describe the effects of varying environmental conditions such as potential hydrogen (pH) and temperature on the rate of enzyme activities
• Describe what is meant by the specificity of enzymes
• Explain the effects of carrying enzyme and substrate concentrations on the rate of enzyme activities
• Demonstrate scientific thinking and communication by formulating hypotheses, designing and conducting experiments, as well as generating and interpreting data.

Hypothesis

• Experiment 1: Effect of Different Substrates on the Rate of Enzyme Reaction

I believe that catechol will have the greatest effect on the potato extract because the potato carries an enzyme that will act as a catalyst against catechol.

• Experiment 2: Effect of Substrate Concentration on the Rate of Enzyme Reaction

I believe that the sample labeled K will have the most pigmentation because the enzyme found in the potato reacts faster with the increase in the amount of substrate found in the test tubes.

• Experiment 3: Effect of Enzyme Concentration of the Rate of Enzyme Reaction

I believe the sample labeled E will have the most pigmentation because potato has an enzyme that will work as a catalyst against the substrate.

• Experiment 4: Effect of pH on the Rate of Enzyme Reaction

I believe that the optimal pH for the samples will be reached at 6 because it is the closest to being neutral on the pH scale.

• Experiment 5: Effect of Temperature on the Rate of Enzyme Reaction

I believe the sample warmed at 70 degrees Celsius will denature because it is too hot for the enzyme to work properly.

Materials

• One small potato
• Knife
• Cutting board
• 250 milliliter (mL) beaker
• Blender
• Cheesecloth
• Rubber band
• Test tubes
• Five test tube racks
• Disposable pipettes
• Deionized water
• Catechol solution
• Substrates: cyclohexanol, (1, 4) – cyclohexandiol, (1,2) – cyclohexanediol, and resorcinol
• Water bath, 37 degrees Celsius
• molar (M) sodium hydroxide (NaOH)
• M hydrochloric acid (HCl)
• pH paper
• Hot plate
• Five thermometers
• Three plastic 250 mL beakers
• One glass 250 mL beaker
• Ice
• Salt

Procedures

Experiment 1: Effect of Different Substrates on the Rate of Enzyme Reaction

1. Make up six test tubes according to table 6.1
2. Label and place all the test tubes in a test tube rack and into a 37 degrees Celsius water bath for 10 minutes
3. After the 10-minute period, observe the tubes and note any color changes. Did any of the tubes change colors? The development of color is visual evidence of the oxidation process catalyzed by the enzyme. All colors should be rated on a scale of 1–10 with 10 being the darkest. Record the data in Table 1 of the lab worksheet
4. Prepare how the results will be presented to the class. Include why different substrates were tried, what should have been seen, and what was seen. Refer to the Review Question 3 for Experiment I, found in the Lab Report Instructions section, and consider the structures of the potential substrates in the presentation

Experiment 2: Effect of Substrate Concentration on the Rate of Enzyme Reaction

1. Make up 11 test tubes according to the following table. Substrate is 0.01 M catechol solution
2. Place 3mL of deionize deionized water into all 11 test tubes
3. Prepare another 11 test tubes each containing 10 drops of the potato extract
4. Place all 22 test tubes into a 37 degrees Celsius water bath for 5 minutes
5.  Quickly mix the potato extract solutions into each of the to-substrate tubes (one potato extract tub for every substrate tube)
6. Return them in the water bath for 10 minutes
7. Remove the test tubes from the bath after the allotted time and compare the intensity of color. The development of color is visual evidence of the oxidation process catalyzed by the enzyme. All colors should be rated on a scale of 1–10 with 10 being the darkest. Record the data in Table 2 of the lab worksheet
8. Prepare how the results will be presented to the class. Include why different concentrations of substrate were tried, what should have been seen, and what was seen.

Experiment 3: Effect of Enzyme Concentration of the Rate of Enzyme Reaction

1. Make up 5 test tubes according to the following table.
2. Add 4 mL of deionized water (in addition to the drops already added) into all five test tubes.
3. Prepare another five test tubes each containing 10 drops of the 0.01 M catechol solution.
4. Place all 10 tubes into 37 degrees Celsius water bath for five minutes.
5. Quickly mix the substrate solution with each of the five potato extract tubes (one potato extract tube for every substrate tubes
6. Return them to the water bath for 10 minutes
7. Remove the test tubes from the bath after the allotted time and compare the intensity of color. The development of color is visual evidence of the oxidation process catalyzed by the enzyme. All colors should be rated on a scale of 1–10 with 10 being the darkest. Record the data in Table 3 of the lab worksheet
8. Prepare how the results will be presented to the class. Include why different concentrations of enzyme were tried, what should have been seen, and what was seen

Experiment 4: Effect of pH on the Rate of Enzyme Reaction