Catechol Oxidase Enzyme Lab Report (Lab Report Sample)

Catechol Oxidase Enzyme Lab Report
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Abstract
Enzymes play a very crucial role in the life of organisms. They catalyze reactions by making them occur under a short period of time. The properties of enzymes are that they only facilitate specific types of substrates and operate within a specific compartment. The enzyme catechol oxidase is one of the most important enzymes in plant cells. This report investigates how this enzyme leads to the formation of Benzoquinone, which is a primary product of its reaction. Further, it investigates enzyme specificity by testing the different reaction rates under different substrates. The temperatures are also known to affect the enzymes differently. This report entails the results of different rates of reaction and effects of different temperatures on the enzyme catechol oxidase. It also discusses why the results for the different temperatures are different. Finally, the effect of pH on enzyme activity is also shown and discussed. The whole experiment gives an extensive highlight of interactions between catechol enzyme and its substrates.
Keywords: Catechol, Oxidase, Benzoquinone, Enzyme, and Activity
Introduction
Background
Enzymes are important catalysts in the life of any organism. The idea of enzymes being biocatalysts of reactions was first discovered in the year 1833 when diastase was found to increase the rate of starch conversion into sugars (Cuesta, Rahman, Furnham, and Thornton, 2015). The full potential of enzymes in technology and medicine, however, was realized in the 20th century following the discovery of methods of enzyme purification and isolation, the classification of enzymes with the help of X-ray diffraction techniques, and the discovery that enzymes are typical proteins that have biochemical activity. The enzymes help in the efficient functioning of the organs and tissues by reducing the reaction time in the body of an organism. Processes would take extremely long periods to be completed in the absence of enzymes. This depicts why enzymes play an essential role in the life processes. There are several functional attributes of enzymes. The substrate or the substance to be reacted in an enzyme-catalyzed reaction binds to the enzyme's active site. The substrate is then converted to the final product that is released into the surrounding solution, setting the enzyme-free for another similar catalyzed reaction. The molecular functions of the enzymes usually occur within specific compartments in the cell. For example, the conversion of D-glucose into α-D-glucose-6-phosphate with the help of the hexokinase enzyme occurs in the cytosol, which is also the pathway for glycolysis (Cuesta et al., 2015). In any of these reactions, an enzyme is never used, but it only catalyzes the reaction and is recycled for other similar reactions. One single molecule of an enzyme is able to simulate hundreds of reactions per minute (School Laboratory Manual, n.d).
In this laboratory experiment, three distinct enzyme experiments involving enzyme catechol oxidase were conducted. This enzyme is essential in plant cells since it catalyzes the reaction that prevents rotting. The aim was to find out; how Catechol Oxidase enzyme works, analyze the effect of pH balance and temperature on its ability to catalyze reactions, and see how enzymes work on specific reactions.
Hypothesis: This experiment hypothesizes that: the catechol oxidase enzyme works by catalyzing the conversion of Catechol to Benzoquinone, which is detected by a color change; it works only on specific reactions; the enzyme works best at its optimum temperature; enzymes work best at their optimum pH.
Procedures
Formation and Detection of Benzoquinone
This step involved the use of Catechol as a substrate and Catechol Oxidase as the enzyme. Three test tubes were labeled as 1a, 1b, and 1c, using a china marker for identification. 1 and 2 cm marks were then placed on each test tube from the bottom. The test tubes were then placed in a rack, and tube 1a was filled with 1 cm of potato extract mixed with catechol oxidase and 1 cm of 1% catechol solution added. Tube 1b was filled with potato extract that contained catechol oxidase, and 1 cm of water was added. Tube 1c contained only 1cm of 1% catechol solution, and 1cm of water was added. All three tubes were shaken and mixed thoroughly. The initial color in the table was recorded against the starting time at 0 minutes, after which all of the test tubes were placed in a 40 degrees water bath for ten minutes. The results were then taken and recorded.
Enzyme Specificity
The three test tubes were labeled 2a, 2b, and 2c, as in the first experiment. Tube 2a was filled with Catechol, Tube 2b was filled with Hydroquinone, while Tube 3c was only filled with water. 1cm of 1% catechol was then added to each of the three tubes. The initial color was recorded. Then the tubes were placed in 40 degrees water bath for ten minutes, and the final color change was recorded.
Effect of Temperature on Enzyme Activity
Four tubes (3a, 3b, 3c, and 3d) were labeled as the previous experiment and filled with 1cm potato extract with catechol oxidase. The four tubes were each placed in temperatures of 5, 25, 40, and 100 degrees for 5 minutes. 1 ml of Catechol was then added immediately after removing the four tubes. The content of the four tubes was then mixed thoroughly, and the color was recorded. They were then returned into their respective temperatures and their final color recoded after 10 minutes.
Effect of pH on Enzyme Activity
Four test tubes were labeled 4a, 4b, 4c, and 4d, and marks of 4cm, 5cm, and 6cm were marked from each tube's bottom. Each of the four tubes was then filled with the phosphate buffers up to the 4cm mark. 1 cm potato extract that contained catechol oxidase was then added to each of the four tubes. 1cm of 1% catechol was then added to each of the tubes and mixed thoroughly. The initial colors were recorded, and the contents were placed in 40 degrees centigrade water bath for 10 minutes.
Results
Table 1: Experiment 1
Formation and Detection of Benzoquinone: Record Color

Time (Minutes)

Tube-1a: Potato Extract and Catechol

Tube 1b: Potato Extract and Water

Tube 1c: Catechol and Water

Color Change On a Scale of 0 – 5 (Description of the overall change)

0

peach

Peach

Clear

1

10

Lighter

Lighter

Clear

1

Product Formation Y/N

y

y

n

0