Rate of Reaction Using Enzymes

This lab activity had students to conduct various tests on enzymes in different environments to determine how the rate of reaction in decomposing hydrogen peroxide (H2O2) to water and oxygen gas was dependent on environmental adjustments. Controls are essential in a lab to help rule out any unnecessary results.

The topic of this lab is on biochemistry.This experiment was conducted to show how cells prevent the build of hydrogen peroxide in tissues. My group consisted of Lekha, Ruth, and Jason. There were used two different concentrations of hydrogen peroxide through this experiment , 1.5% and 3%. By testing two different types it is easier to understand how the H2O2 and catalase react with one another. To do this both the yeast, which was our catalase, and H2O2 were mixed together in a beaker. Each concentration was tested out twice for more accurate results . 1.5% concentrated H2O2 had an average reaction rate of 10.5 seconds while 3% concentrated H2O2 had an average reaction rate of 7.5 seconds. From this experiment we learned that by increasing the concentration of H2O2 and chemically combining it with a catalase it will speed up the reaction. Enzymes speed up chemical reactions . The independent variable in this experiment was the concentration of the H2O2. Some key vocabulary words are Catalase, enzyme, hydrogen peroxide ( H2O2), and concentration.

For a detailed list of required materials, refer to the enzyme lab handout section C. The independent variable in this study was temperature. The dependent variable was rate of reaction, measured qualitatively on a scale of one to five based on the number of bubbles observed as the reaction took place. The amount of liver and H2O2, the ambient temperature, and the observation time allotted for each reaction were control variables that were kept constant throughout.

In the first part of the enzyme lab, we mixed a substrate and an indicator with an enzyme. There was also a neutral buffer in each of the chemical mixtures. The neutral buffer regulated the pH to around 7. We got a color palette and once we mixed each together, we observed and saw a change in the color of the substance. The darker and more brown the substance got, the more oxygen produced by the reaction. Our results showed that amount of oxygen produced increased about 10% a minute until it sort of equilibrated at 4 minutes and didn’t change to the fifth minute mark. If we were to change anything we did in the experiment, we would make our comparisons to the chart more precise. Overall we thought it

The hypothesis was that if we investigated samples from different kingdoms, then the rate of reaction run by enzymes would change, and enzymes in animal cells would run reactions at the fastest rate, while enzymes in plant cells would run reactions at the slowest rate. The independent variable for this experiment was the samples of different kingdoms; the dependent variable was the rate of reaction run by the enzyme. To prepare a 500 ml sample, 21g of chicken liver was blended and mixed with water; and the sample of potato and the sample of an active yeast was made the same way. Then, a fermentation tube was marked from the top by centimeters and filled with hydrogen peroxide solution. Next, 1 ml of chicken liver blend was added into the tube by a pipet, and the time for 1 cm peroxide solution to be consumed was measured.

Catabolic pathways release energy by breaking down complex molecules into simpler compounds; and energy is stored in the cell until its needed.

It is predicted that enzyme activity will speed up from 0 to 37 degrees and then rapidly slow down or stop altogether at 55 degrees. Methods For this experiment the dependent variable will be the amount of product, oxygen, produced by the enzyme catalase breaking down hydrogen peroxide. The independent variable will be temperature. Four temperatures will be tested on the enzyme to see how much product will be produced. Controlled variables will be the amount of enzyme, hydrogen peroxide and water used in the test tubes, as well as the volume of the nalgene bottle (250 mL) used in testing to measure the product.

This experiment looked at how the presence of enzymes can change the rate of reaction. An enzyme is a specialized protein that catalyzes chemical reactions (Freeman, et al, 2014,p.46). If a reaction occurs the reactants must interact with a specific orientation and there must be enough kinetic energy to reach the activation energy required for the reaction (Freeman, et al, 2014, p.55). Enzymes are an important part in chemical reactions because they move the reactants together in the orientation needed for the electrons to interact, and they lower the activation energy needed, which allows the reaction to occur faster (Freeman, et al, 2014, p.55).

Problem/Info: Enzymes are large protein structures, also known as macromolecules and catalysts. They aid in the acceleration of chemical reactions by binding to another substance known as a substrate, converting it into different products that are more easily broken down called products. Only a small portion of the enzyme actually aids in catalyzing the substrate: the active site. When an enzyme is in specific conditions they tend to react quicker while in other, generally extreme, conditions the enzyme can be broken apart and rendered unusable, this is called denaturation. In the experiments conducted, an enzyme known as catalase, generally found in yeast, will be soaked onto a tiny paper circle and dropped into hydrogen peroxide H2O2. The catalase will break the hydrogen peroxide into oxygen and water. The oxygen inside of the paper will eventually be in a quantity that causes the paper to rise to the top of the hydrogen peroxide. The entire experiment is based off of observations of this piece of paper.

We used this information to form our hypothesis, which was that the 100% concentration test would have the highest reaction rate because the more enzyme is the more active sites there are, so more reactions can occur, and the the Hydrogen peroxide will be decomposed faster, giving it a higher rate. However, the results of our experiment did not support this. Like explained before, the test that resulted in the highest rate was the one with 50% concentration. It is unknown why this occurred. The sources provided in class, a graph, showed that there should be linear growth between concentration and rate, which supports our hypothesis. Fig. 2 shows that the reaction rate plateaus towards the end of the 50 seconds, but this is because of the limited and constant amount of substrate, so it slowed down when the Hydrogen peroxide ran out. Our data did not support our hypothesis, but the class source support our

We created solutions of different concentrations of the substrate, hydrogen peroxide. The concentrations included 0%, which was 4 mL of plain water, .125%, .25%, .5%, 1%, 3%, and 6% hydrogen peroxide. To keep outside factors, such as temperature, from affecting the results of the enzymatic rate of reaction, we kept the two enzyme solutions in ice, and had each of the substrate solutions in room temperature. The 0% substrate solution acted as the control group, measuring what happens with the filter paper if there is no substrate. The rate of reaction was measured by taking bits of the same size Whatman #1 filter paper, by using a hole punch, dipping it in the enzyme solution for two seconds, letting the excess soak into a paper towel, and putting the paper into the substrate solutions. As the filter paper first touched the water, we started timing to measure how long it would take for the paper to lift from the bottom of the glass. We did this with both the cantaloupe and avocado, twice each, to have two trials for each percentage of each solution. We then took the average of both tests and found the rate of reaction by dividing one over the average of the rate of reaction for each

Enzymes catalyze biological systems by speeding up the chemical reactions included. Enzymes developed from the peroxidase that is obtained from the different roots reacts with the hydrogen peroxide, which releases H2 and water. The extra hydrogen is indicated by the color change of the solution that is used to measure the rate of enzyme activity. When the rate of enzyme activity was high, the activity always occurred in the roots in the beginning stages of their development. However, when the rate of enzyme activity was low during the roots’ development, sucrose was present. Sucrose was not present in roots when the tissues consisted of high activities of acid invertase.

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.

Then you will put a solution of activated yeast in a beaker. Use the forceps to dip the paper disk into the beaker, which contains the catalase enzyme. Next, use the forceps to transfer the paper disk into the bottom of the beakers with hydrogen peroxide. You will then measure how long it takes for the bubbles to carry the disk to the top of the beaker. Measure the amount of seconds it takes for the paper disk to float to the top in the data table. Repeat the steps until you have at least 3 trials for each hydrogen peroxide solution.

An enzyme is a catalyst that speeds up chemical reactions, but it does so with out change the chemical reaction its self. Ph is the concentration of hydrogen ions it ranges from 1-14 when the pH is at 7 it is considered neutral. Water has a pH of 7 which is neutral on the pH scale. In this lab we will be experimenting to be how the different number of pH effect the rate the enzyme reacts. Since water is neutral at 7 we have a hypothesis that its amount of form inside the test tube should be higher or have more form then something that is more acidic, which means is pH is lower than 7. The amount of enzyme and the amount of concentration substrate should be equal since it’s an equally balanced formula and you can not make more then what you put in that means if the substrate concentration increases then the enzyme activity should also increase. We will be using hydrogen peroxide which is a liquid with strong oxidizing properties to test are hypothesis. “Because of