Tyrosinase Lab

In this experiment, 4 grams of peeled turnip was used to prepare the enzyme extract opposed to the 1 gram of turnip suggested by Fundamentals of Life Science. Along with the change to the amount of turnip used, the amount of 0.1M phosphate buffer used to prepare the enzyme extract was changed from 50mL to 30mL. The affect of temperature on enzyme activity was not

In this lab or experiment, the aim was to determine the following factors of enzymes: (1) the effects of enzymes concentration the catalytic rate or the rate of the reaction, (2) the effects of pH on a particular enzyme, an enzyme known and referred throughout this experiment as ALP (alkaline phosphate enzyme) and lastly (3) the effects of various temperatures on the reaction or catalytic rate. Throughout the experiment 8 separate cuvettes and tubes are mixed with various solutions (labeled as tables 1,3 & 4 in the apparatus/materials sections of the lab) and tested for the effects of the factors mentioned above (concentration, pH and temperature). The tubes labeled 1-4 are tested for pH with pH paper and by spectrophotometer, cuvettes 1a-4a was tested for concentration and cuvettes labeled 1b-4b was tested for temperature in four different atmospheric conditions (4ºC, 23ºC, 32ºC and 60ºC) to see how the enzyme solution was affected by the various conditions. After carrying out the procedures the results showed that the experiment followed the theory for the most part, which is that all the factors work best at its optimum level. So, the optimum pH that the enzymes reacted at was a pH of 7 (neutral), the optimum temperature that the reactions occurs with the enzymes is a temperature of 4ºC or

The use of multiple test tubes and Parafilm was used for each experiment. Catechol, potato juice, pH 7 phosphate buffer, and stock potato extract 1:1 will be used to conduct the following experiments: temperature effect on enzyme activity, the effect of pH on enzyme action, the effect of enzyme concentration, and the effect of substrate concentration on enzyme activity. For the temperature effect on enzyme activity, three test tube were filled with three ml of pH 7 phosphate buffer and each test tube was labels 1.5 degrees Celsius, 20 °C, and 60 °C. The first test tube was placed in an ice-water bath, the second test tube was left at room temperature, and the third test tube was placed in approximately 60°C of warm water. After filling the test tubes with three ml of the

This lab was performed in order to discover the activity of the enzyme catecholase in different pH levels as well as its absorbance in differently concentrated solutions. A spetrophotometer was used to measure the absorbance of the enzyme catecholase in different pH solutions as well as to measure the absorbance of catecholase in solutions with different concentrations of potato juice and phosphate buffers. Absorbance of the enzyme catecholase was at an optimum level when pH was close to neutral. When pH was acidic or basic, the catecholase was less effective. Also, when there was a higher concentration of potato juice and a lower concentration of phosphate buffer, absorbance of the enzyme increased.

The independent variable in this investigation is pH. Each individual enzyme has it’s own pH characteristic. This is because the hydrogen and ionic bonds between –NH2 and –COOH groups of the polypeptides that make up the enzyme, fix the exact arrangement of the active site of an enzyme. It is crucial to be aware of how even small changes in the

As the enzyme concentration increased so too did the activity rate. The relatively level areas show where there was substrate depletion.

The rate of enzyme activity of Lactase. The change in absorbance is key in determining the optimal salt concentration. The enzyme activity was measured by the use of the Spectrophotometer. Over the course of the experiment, the lowest concentrations showed the largest change in absorbance.

This paper reports experiments on the stereospecificity observed in the monophenolase and diphenolase activities of mushroom tyrosinase and the inhibiting effects of thiourea, cinnamic acid and benzoic acid. The enantiomer L-DOPA and D-DOPA were assayed. The Vmax and Km values obtained for each were different. Thus mushroom tyrosinase showed

After the substrate solution was added, five drops of the enzyme were quickly placed in tubes 3, 4 and 5. There were no drops of enzyme added in tubes 1 and 2 and in tube 6 ten drops were added. Once the enzyme solution has been added the tubes were then left to incubate for ten minutes and after five drops of DNSA solution were added to tubes 1 to 6. The tubes were then placed in a hot block at 80-90oC for five minutes. They were then taken out after the five minute period and using a 5 ml pipette, 5 ml of distilled water were added to the 6 tubes and mixed by inversion. Once everything was complete the 6 tubes were then taken to the Milton Roy Company Spectronic 21 and the absorbance of each tube was tested.

The enzyme activity is affect by its surroundings especially when pH, temperature, and the concentration of activator and inhibitor are involved. When the pH rise or drops out of the enzyme stretch in tolerance, the structure of the protein can be alter or in other worlds denatured. Most of the enzyme in the bodies of humans

The use of the Protease Inhibitor, 1.0mM PMSF, resulted in the highest amount of Tyrosinase activity, which was 13.9 units per milliliter of latent enzyme. The Protease Inhibitor, 0.1mM PMSF was therefore, most effective at extracting Tyrosinase. The Protease Inhibitor, 1.0mM EDTA, resulted in the second highest amount of Tyrosinase activity, which was 12.9 units per milliliter. The Protease Inhibitor, 1.0mM EDTA was therefore the second most effective at extracting Tyrosinase. The use of the Protease Inhibitor, E-64, resulted in the third highest amount of Tyrosinase activity, which was 12.3 units per milliliter. The Protease Inhibitor, E-64, was therefore the third most effective at extracting Tyrosinase. The use of the Protease Inhibitor, Pepstatin, resulted in 9.9 units per milliliter of Tyrosinase activity. The Protease Inhibitor, Pepstatin, was therefore the least effective at extracting the enzyme Tyrosinase. The concentration of hydrogen ions, or as it is more commonly known, the pH, had a huge effect on the extraction of Tyrosinase. At a pH concentration of 5.5 and lower (pH = 3), the Tyrosinase enzyme activity was very low to nothing at all. At pH concentration of 6 to 8, the enzymatic activity of Tyrosinase greatly increased. It is known that every enzyme has its own optimum pH at which it performs at its best. According to the graph in this journal, it is observed that this optimum pH for the

Temperature, pH, enzyme concentration, and enzyme inhibitors are all factors that influence the activity of the

The materials needed for the experiment is a vial of the blood serum containing the enzyme alkaline phosphatase, a stock solution of 10mM of p-nitrophenyl phosphate in water (substrate). 5mM of phenyl phosphate in pH10 buffer solution, 0.1NaOH solution to stop enzyme activity, buffer solution at pH10 and a vortex mixer to mix the solution.

Latent enzyme activity is activity that the enzyme is capable of doing when active. It refers to the activity that is prevented by the inability of the substrate to cross the membrane of the organelle in which the enzyme resides. This data displays this as very little activity is observed in the homogenate and triton and the intact mitochondria. This activity is probably due to or substrate passing into the mitochondria. The small level of activity in the homogenate plus Triton could be explained if some

To study the effects of temperature, pH, enzyme concentration, and substrate concentration there were certain steps that were followed in order to conduct this experiment. Each factor had a separate procedure to follow to find how each had a different effect on the enzyme.