Enzymes are proteins that catalyze (speed up) biological reactions in an organism by lowering the activation energy of a reaction. They do this by either straining the bonds in a molecule so that is easier to break up or by placing separate molecules/elements close to each other so that bonds are formed. Enzyme activity is influenced by an array of different factors such as enzyme concentration, substrate concentration, temperature, pH and inhibitor concentration. All of these affect the rate of reactions of enzymes and some such as temperature, inhibitors and pH can under circumstances cause enzymes to become permanently affected.
Catalase is an enzyme found in almost all organisms on earth exposed to Oxygen. It breaks down H2O2, a dangerous
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Due to the range of concentrations the anticipated trend was not seen, because the enzyme did not become the limiting variable. Furthermore, from 1% to 3% the intervals were .5% instead of .25% a smaller interval would make the data more clear. This had a large impact on the yielded results as the anticipated trend was not observable. The range of the concentration should be from 0.00% to 5% with .25% intervals to make the data more clear and to see if the hypothesized trend would be observable. If the trend would still not be observable the concentration could be elevated even …show more content…
Extension:
Comparing the trends shown in enzyme activity increase in catalase activity when no inhibitors are added to when a set amount of competitive inhibitors are added and a set amount of non-competitive inhibitors are added could extend this lab.
Another possible extension is comparing the efficiency of catalase to other peroxidases by conducting the same experiment and seeing which enzyme will have the highest rate of reaction overall.
Furthermore, one could compare the amount of catalase in an organism/part of an organism by finding the rate of reaction of different origins of catalase under the exact same conditions with an excess of hydrogen peroxide
The more acidic a substance is the less oxygen it will produce when going through a chemical reaction. During the Lab “How Do Changes in pH Levels Affect Enzymes Activity”, the researcher conducted an experiment to test the effects that an acidic, neutral, and a base substance will have when combine it with hydrogen peroxide. The data table shows that HCL (acidic substance) barley produced any oxygen at all when it was combining with Hydrogen Peroxide. The pH level for HCL was 2.5; this level indicates that the substance was very acidic. When the H2O and NaOH were tested they produced more bubbles than HCL. NaoH produced a little more bubbles than HCL. The pH that NaoH produced was a 9, which is a base. H2O produced more bubbles than both substances;
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 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
This process is called decomposition as two hydrogen peroxide molecules are broken down into oxygen and two water molecules.
We used apple, potato, and chicken liver to prove that not only beef liver contains catalase. The group conducted three experiments: one contained potato and H2O2, another had apple and H2O2, and the last had chicken liver and H2O2. We added 2mL of hydrogen peroxide (H2O2) to all three test tubes. The bubbling effect proved that all three had catalase in them. We realized that the more the substance bubbled the more catalase it contained, and that the less it bubbled, the less catalase there was. We also rated the reactions by the speed of the reaction in seconds, like we learned in part
Enzymes are catalytic proteins, meaning they speed up – but do not create – chemical
Its role as an enzyme is to quickly break down hydrogen peroxide (H2O2) into water and oxygen, preventing cellular damages. H2O2 is produced as a harmful by-product in all organisms that use molecular oxygen, so catalase is especially abundant in liver cells of humans and other organisms, because the liver is an organ that detoxifies many harmful substances including peroxides (Lab Manual). The catalase and hydrogen peroxide reaction process is as seen as below:
As seen on table 1, the hypothesis in the introduction of this lab has been supported by the procedures. As the temperature varied from catalases optimal of 37° C, the reaction rate of catalase decreased. 37°C had the highest reaction rate of the three, at 3, while 4°C had the middle rate of reaction at 2.5, and 100° C had the lowest reaction rate of 0.5.
However, there exist a natural process occurs which converts hydrogen peroxide into water and oxygen gas, thus preventing potential harm to the body. This reaction is illustrated by the equation
Enzymes are biological catalysts, which speed up the rate of reaction without being used up during the reaction, which take place in living organisms. They do this by lowering the activation energy. The activation energy is the energy needed to start the reaction.
The chemical hydrogen peroxide(H₂O₂) is broken down by the enzyme catalase. Hydrogen peroxide is a byproduct formed in cellular reactions that, if not broken down, could inflict severe damage to the cell. Catalase is an enzyme that breaks down hydrogen peroxide in to water and oxygen. How efficient and strong the enzymes reaction to break down H₂O₂ determines largely on temperature and pH level. An enzyme only functions within a set pH and temperature range. Beyond that it becomes denatured, rendering it useless. The purpose of this lab is to determine at which temperature and pH level the enzyme catalase reacts best. Catalase in chicken and beef livers will be used to do the lab because enzymes still function after death as long as they are kept refrigerated at a low temperature.
In the comparison of the two reactions occurring with the 80% in part A and B it makes sense that the rate of reaction in part B is slower because of the non-competitive inhibitor that was acting upon the catalase. But, the rate of reaction seems to be too low for the result too be realistic indicating a human error and causing it to be slightly unreliable. Failing to change the hydrogen peroxide from part A to a new solution in part B may be an example of human error. An experimental error that may have affected the results obtained during the experiment was the labs failure to mention to mix the two substances, hydrogen peroxide and copper II sulphate in part B. Failure to mention this simple instruction may have led to the outliers in time retrieved in part B for the experiment. In the first trial when the filter timed out at 240 seconds at the bottom of the beaker, it may have been caused by the un-dissolved copper II sulphate still at the bottom of the beaker. Another experimental error was that during the experiment it was stated that if one was able to hurry and do the first two trials quickly then there may be time for a third
An enzyme is a substance that acts as a catalyst in living organisms by speeding up the rates of chemical reactions in that organism (Coker, 2015). Enzymes, which are proteins, are the most common biological catalysts (Herz, 2017). Enzymes are able to increase the rate of chemical reactions by lowering the activation energy needed for a reaction to occur. However, one thing that enzymes do not do is supply free energy to a reaction or change the total energy of a reaction (Herz, 2017). Enzymes also follow a rule of substrate specificity. This means that each enzyme catalyzes the reaction of a single substrate or a group of closely related substrates, and is also the reason why a typical cell in the human body needs over 4,000 enzymes to function (Herz, 2017). Enzymes are also reusable, because they are not consumed in the reactions they catalyze (Coker, 2015). Temperature and pH are two main factors that affect enzyme activity. When fluctuations in temperature and pH occur, an enzyme may denature and lose its function (Coker, 2015). For most enzymes, extremely high temperature and an extremely low and acidic pH can cause the protein to denature.
In this lab, we had learned how both temperature and pH affect the enzyme activity. We created a hypothesis and later tested them using 4 procedures. These procedures included test tubes, cuvettes, baths with different temperatures, thermometers, chemicals and spectrophotometers. We had created graphs to show a visual of the data we had collected rather than just simply showing numbers. Having a graph was very helpful, so we can better compare the data. This lab had helped us better understand enzymes.
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