Based on the outline below, can you help with the report: Outline: Enzymes are m

Question

Based on the outline below, can you help with the report:

Outline:

Enzymes are mostly proteinaceous in nature. They are affected by changes in pH. The most favourable pH at which the enzyme is most active is known as the optimum pH. pH values other than optimum pH leads to reduction in enzyme activity. Extremely high or low pH values may cause the enzyme to completely loss its activity.

Principle of our experiment :

Amylase is an enzyme that acts on starch (substrate). 1% Iodine solution is employed to test the activity of enzyme. Starch reacts with iodine solution to give blue black coloration. Hence we will observe the color change.

Starch + I2 à blue-black color

APPARATUS

Equipment

Test tubes

Pipettes

Pasteur pipettes

Beaker, 250 mL

Test tube rack

Effect of pH

Prepare 0.1 M pH buffer solutions ranging from pH = 4.5 to pH = 9.0 in increments of one pH unit.

Add an equal volume of one of the above buffer solutions to 5.0 mL of the 1% starch solution prepared.

Start the enzymatic digestion process by adding 1 mL of human salivary enzyme solution; shake and mix.

Let the hydrolysis reaction proceed for exactly 10 minutes at 25 0C.

Add 0.5 mL HCl stopping solution (0.1 N).

Add 5 mL iodine solution to develop color.

Shake and mix.

The solution should turn deep blue if there is any residual, unconverted starch present in the solution. The solution is brown-red colored for partially degraded starch, while it is clear for totally degraded starch.

Control in the experiment would be the one containing water in place of buffer solutions

Observations :

pH range 6.5 to 7.5 will give clear solutions since it is an optimum pH range for amylase, hence it will completely degrade the starch present in the test tube.

Other pH values 4.5-6.0 = brown-red colored solutions since enzyme will degrade starch partially

2.5-4.5 pH value = deep blue color solutions obtained since enzyme will be completely denatured and has no activity, thus the solution contains undigested starch which will react with iodine solution to give deep blue color.

***Option 1 Final Project Report:

Remember, the goal of this project is for you to evaluate the effect of an acid on enzymatic activity. As part of this assignment, you must identify your source of enzyme and the acid used. As you work though this project, you must also make sure that the following questions/points are addressed in your report:

What question are you asking? Clearly state your hypothesis.

2. Design an experiment. Provide a detailed account of the materials and methods used to conduct the experiment. Also include the methods for data collection and analysis.

3. Conduct the experiment and record your results. Include photographs of your experiment. What did you observe? Which samples showed bubbling?

4. Use your knowledge about enzymes to interpret your results. It may be necessary for you to refer to your textbook. What effect does the acid have on the enzyme?

5. Was your hypothesis supported? What is your conclusion?

6. Cite all references used to complete your project.

Explanation / Answer

INFLUNCE OF PH ON THE ACTIVITY OF CATALASE ENZYME  

INTRODUCTION

Enzymes are vitally important for every living organism, because without them the reaction within the cells would occur slowly to sustain life. However there are many factors which influence the enzyme activity and one of them is pH. Catalase of potato tuber cells will be the enzyme used in experiment .

Catalase breaks down H2O2 (hydrogen peroxide) into water and oxygen.

H2O2 is a toxic substance formed during anaerobic respiration

HYPOTHESIS

Different pH values influence the activity of Catalase. It was obtained from the literature that the, range of pH values at which Catalase works is 4-9 pH With an optimum pH of the Catalase is 7.

MATERIALS:

Scalpel, cork, borer, petri dish, boiling tubes, support stand, monometer tube with rubber bung (2mm diameter), beakers 10ml, pipette, clock, potato(50ml), Citric acid phosphate buffer pH:3,4,5,6,7,8, and tap water

METHOD

1. With a cork borer a cylinder of potato tuber tissue of about 1cm in diameter and at least 6cm long was cut. The ruler was placed beside the cylinder and it was cut into 60 discs 1mm thick. as the discs were cut, they were immediately placed under water in petri dish.

2. First the boiling tube was placed in a support stand and the monometer tube was filled with water up to the mark. Then the boiling tube was filled with 56ml of buffer solution at ph 3. Carefully 10 potato discs were added. Then, 5ml of hydrogen peroxide was added to the boiling tube and it was carefully mixed.

3. As soon as the hydrogen peroxide was added, the rubber bung was sticked on to the boiling tube and the clip at the top of the boiling tube was closely in a way, that it is proved an airtight seal.

4. As a reaction began and the oxygen was produced the water, which was in monometer was pushed down the left hand side of the monometer tube. Time how long did it take for the fluid to rise through a distance of 5cm in the right hand side tube was measured. The result was recorded.

5. As soon as the water has reached level in the right hand side, the clip at the top of the boiling tube was opened so that the manometer water returned to its original position.

6. Points 3-5 of the procedure were repeated 3 times more and the results were recorded. The average reading was worked out and recorded.

7. After 4 measurements the rubber bung was removed and the tube was washed out.

8. Five further tests were carried out, each with a fresh set of potato discs. The same procedure was followed but with buffer solutions 4,5,6,7, and 8 in turn. At every time a clean beaker was used to measure 5 ml of buffer and hydrogen peroxide. The data was recorded.

Result:

Mean values of time at which oxygen was evolved during decomposition of hydrogen peroxide catalyzed by Catalase in manometer tube at different pH values is plotted

Conclusion:

The data support that the value of pH at which Catalase works most efficiently is app 7. When the pH is lowered from 7 to 3 the efficiency of Catalase decreases more than half. Also, when the pH is greater than 7 efficiency of the enzyme begins to decrease.

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