Lab 1 again Essay

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

This experiment looked at how substrate concentration can affect enzyme activity. In this case the substrate was hydrogen peroxide and the enzyme was catalase. Pieces of meat providing the catalase were added to increasing concentrations of hydrogen peroxide in order to measure the effect of hydrogen peroxide concentrations on the enzyme’s activity. The variable measured was oxygen produced, as water would be too difficult to measure with basic equipment.

In the experiment we used Turnip, Hydrogen Peroxide, Distilled Water, and Guaiacol as my substances. On the first activity, Effect of Enzyme concentration of Reaction Rate for low enzyme concentration, we tested three concentrations of the turnip extract, and hydrogen peroxide. For the Turnip Extract I used 0.5 ml, 1.0 ml, and 2.0 ml. For hydrogen peroxide we used 0.1 ml, 0.2 ml, and 0.4 ml. We used a control to see the standard, and used a control for each enzyme concentration used. The control contains turnip extract and the color reagent, Guaiacol. We prepared my substrate tubes separately from the enzyme tubes. My substrate tube

Students will be observing normal catalase reaction, the effect of temperature on enzyme activity, and the effect of pH on enzyme activity in this experiment. The enzymes will all around perform better when exposed in room temperature than when it is exposed to hot and cold temperatures. This is based on the fact that the higher the temperature, the better the enzymes will perform, but as the temperature reaches a certain high degree, the enzymes will start to denature, or lose their function.

My graph shows there is an almost perfect positive correlation between the hydrogen peroxide concentration and the rate of the catalase enzyme reaction, with a correlation coefficient of 0.99. The rate of reaction at 1% concentration was 0.46cm3 oxygen produced per minute and the lowest recorded rate. For 3% was 1.33cm3 per minute, and for 6% was 2.17cm3 per minute and was the highest recorded rate. The

Lab six requires students to observe the effects of pH and enzyme concentration on catecholase activity. Enzymes are organic catalysts that can affect the rate of a chemical reaction depending on the pH level and the concentration of the enzyme. As pH comes closer to a neutral pH the enzyme is at its greatest effectiveness. Also at the absorbance of a slope of 0.0122 the enzyme is affected greatly. The pH effect on enzymes can be tested by trying each pH level with a pH buffer of the same pH as labeled as the test tube and 1mL of potato juice, water, and catechol. This is all mixed together and put in the spectrophotometer to test how much is being absorbed at 420nm. As the effect on enzyme concentration can be tested almost the same way. This part of the exercise uses different amounts of pH 7-phosphate buffer and potato juice, and 1mL of catechol mixed together in a test tube. Each substance is put in the spectrophotometer at a wavelength set tot 420nm. The results are put down for every minute up to six minutes to see how enzyme concentration affects reaction rate. The results show that the pH 8 (0.494) affects the enzyme more than a pH of 4 (0.249), 6 (0.371), 7 (0.456), and 10 (0.126). Also the absorbance is greatest at a slope of 0.0122 with test tube C that has more effect on the reaction rate, than test tube A, B, and D.

6.  What reaction would you expect when performing a positive control in the catalase assay? I would expect a reaction to occur and bubbles to form.

However, the rate of reaction only increases for a certain period of time until there is lesser substrate molecules than the enzyme molecules. The increase of enzyme concentration does not have effect if there are lesser substrate molecules than enzyme molecules initially.

The two experiments investigated measure the activity of the enzyme, catechol oxidase. Specifically, they investigate the effect of decreasing amounts of enzyme on rate of reaction and effect of decreasing amounts of substrate on rate of reaction. Enzymes are proteins with specific structures determined by the sequence of amino acid used to accelerate and regulate biochemical processes; enzyme activity can be measured using the rate at which the reaction catalyzes and can be expressed in concentration of substrate or product. Catechol oxidase, the enzyme used in the experiments, can be found in potatoes and catalyzes the oxidation of catechol to ortho-quinone. This substance turns fruits brown when cut open. The ortho-quinone produced in the experiments was used to determine the reaction rate. The experiments involved enzyme dilutions mixed with water and catechol in experiment II and .026M catechol with water and potassium phosphate in experiment III. Both experiments were measured using a spectrophotometer. My hypothesis for experiment II stated that as the enzyme concentration increased the rate of reaction would also increase at a constant rate, and my hypothesis for experiment III stated that the substrate concentration would increase as the rate of reaction increased at a constant rate. The results concluded that in experiment II the enzyme concentration increased at a constant rate, while the reaction rate increased. The experiment III concluded that the

We increased the substrate, catechol, while maintaining the enzyme, catecholase, at the same volume. We came to the hypothesis that if the substrate was increased, then the rate of reaction would increase as long as there is enzymes to react with. The third experiment involved how temperature would affect enzyme activity. This was done by placing certain vials in certain temperatures and then analyzing the data in the spectrophotometer. We came to the hypothesis that if the temperature was increased, then the reaction rate would increase until it reaches the optimal temperature after that the reaction rate would decrease. This is because the enzyme will start to denature if the temperatures get too high or too low. The fourth experiment deals with how pH affects enzyme activity. For this experiment different vials with catecholase and different pH’s were observed under a spectrophotometer to see how the enzyme would be affected. We found our hypothesis to be, if pH is raised, then the reaction rate will increase until it reaches the optimal pH. The reaction rate will increase until the optimal pH because after the optimal pH, the enzyme will start to denature and not function as it

This is different than the H2O2 with catalase which started at 23.5 degrees celsius before the catalase was added, but then increased temperature to a peak of 33 degrees celsius and after 5 minutes to a final temp of 29.5 degrees celsius. This is a proof that a chemical change occurred meaning the H2O2 was broken down using the enzyme Catalase, which sped up the chemical reaction. This chemical reaction is not seen for the second hypothesis, if the boiled catalase solution is added to the H202, then there will be no significant increase in temp compared to the control. That means that the hypothesis is correct, which is supported by the results. Compared to the control, which had a steady temp of 23.5 degrees celsius, the boiled catalase when added also stayed in the range of 23.5 degrees celsius.

Another variable tested was decreasing the temperature in the reaction of the enzyme catalase. In these tests, the reaction rate showed a slight decrease because the decreasing of temperature makes molecules move slower, which leads to less of an reaction rate. Tests showed that in one instance when a decreasing of temperature was added, the reaction rate was 9 ml/min. This proves that the decrease of temperature slowed down the reaction rate.

Enzymes are high molecular weight molecules and are proteins in nature. Enzymes work as catalysts in biochemical reactions in living organisms. Enzyme Catecholase is found on in plants, animals as well as fungi and is responsible for the darkening of different fruits. In most cases enzymatic activities are influenced by a number of factors, among them is temperature, PH, enzyme concentration as well as substrate concentration (Silverthorn, 2004). In this experiment enzyme catecholase was used to investigate the effects of PH and enzyme concentration on it rate of reaction. A pH buffer was used to control the PH, potato juice was used as the substrate and water was used as a solvent.

The efficiency of the enzyme catalase is affected by the temperature of its surroundings. The experiment done to prove this, was by putting hydrogen peroxide on chicken liver which contains the enzyme catalase, in different temperature water and seeing how much water and oxygen it would produce. The amount of products (water and oxygen) produced in 10 minutes will be able to tell the reaction rates in each temperature.

This experiment is designed to analyze how the enzyme catalase activity is affected by the pH levels. The experiment has also been designed to outline all of the directions and the ways by which the observation can be made clearly and accurately. Yeast, will be used as the enzyme and hydrogen peroxide will be used as a substrate. This experiment will be used to determine the effects of the concentration of the hydrogen peroxide versus the rate of reaction of the enzyme catalase.