Introduction:
Plant leaves contain many enzymes, and the rate of enzyme reaction differs with the concentration of the substrate present. One of the enzymes present in any plant’s leave is catalase. Catalase is an extremely reactive enzymes that do not need cellular reductants, as they usually catalyse a dismutase reaction (Mhamdi, Queval, Chaouch, Vanderauwera, Breusegem & Noctor 2010) One may find out the rate of catalase reaction through placing different plant leaves of the same species in different concentrations of hydrogen peroxide, and measuring the time taken for the leaf to flip over or counting the amount of oxygen bubbles produced in a set time. In this experiment, the rate of enzyme reaction was measured by measuring the time
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This is because when catalase reacts with hydrogen peroxide, water and oxygen is formed (Mhamdi, Queval, Chaouch, Vanderauwera, Breusegem & Noctor 2010). Hence, as the concentration is not high, there will be less hydrogen peroxide for the catalase to catalyse, hence less oxygen will be produced and thus the leaf in the lowest hydrogen peroxide concentration solution will take the longest time to rise. Therefore, it was predicted that the leaf that would take the longest time to rise to the surface was the leaf in the 1% hydrogen peroxide concentration solution, and the leaf that would take the shortest time to rise would be the leaf in the 5% hydrogen peroxide …show more content…
In the experiment, the same volume of hydrogen peroxide was used for each set up. We used 20cm3 of hydrogen peroxide so that the only factor affecting the rate of enzyme reaction would be the concentration of hydrogen peroxide and not any external factor.
The second control variable was the size of the leaf used as the size of the leaf affects rate of enzyme reaction.
Another one of the control variables was the size of the leaf. This was because the bigger the size of the leaf, the more catalase is present. Hence, each leaf was cut to the dimensions 2 by 3cm so as to ensure that the only factor affecting the rate of enzyme reaction was the concentration of hydrogen peroxide and not the amount of enzymes present.
The third control variable was the species of brassica rapa leaves only as the species of leaf used affects rate of enzyme reaction.
This is because different species of leaves have different amounts of catalase. Hence, if the species of the leaf is different, the results will be inaccurate and unreliable as the rate of enzyme reaction will not be purely based on the concentration of hydrogen peroxide, but will also be dependant on the amount of substrates in the different leaves.
Method:
Equipment
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As pH increases or decreases to get closer to the optimal pH --in this case it is 7 for this particular enzyme-- the rate of reaction peaks and is highest at that point, which is described by the molecular shape and structure of the enzyme at its optimal pH. When turnip peroxidase is at pH 7, the active site is able to fit perfectly with the substrate, therefore explaining why the reaction rate is fastest at this point. Accordingly, if the active site is disrupted, the substrate cannot fit perfectly causing the reaction rate to slow down. This can be supported by the data because the reaction rate gradually increased from pH 3 to pH 7 and reached its maximum at pH 7. Once it did reach the optimal pH, the reaction rate continuously decreased
Catalase Activity on Substrate Based On Gas Pressure Production Rate Name of the Class Author’s Name Date Enzymes are organic compounds which act as catalysts and speed up biological reactions in biological organisms. They are not destroyed or changed during the reaction but rather they are used over and over again to catalyze many more reactions. Their activity may be affected and altered by factors such as temperature, substrate concentration, enzyme concentration and Ph.
Title: Enzymes Abstract: Enzymes can catalyze chemical reactions by speeding up the chemicals activation energy. Temperature and pH are just two of the factors that affects enzymes and their involvement with chemicals and the way they function. Throughout this experiment, we conducted a study on peroxidase, which is an enzyme. The following information consist of the recordings of when it was exposed to four different pH levels to come up with an optimum pH and IRV at the end. Introduction: Enzymes are proteins that are used in reactions in living organisms.
After record your data and determine the absolute rate of the enzyme-catalyzed reaction. Based on the data and observations the hypothesis was accepted. It was accepted because when pH were changed to a variety of levels the transmittance began to get higher reaction rates. The increased absorbance means greater amount of product and a higher reaction rate will be produced.
It was hypothesized that the optimal pH for the enzyme was pH 7 while the 1.0 ml peroxidase would have the best reaction rate. At the end of the experiment the results prove the hypothesis to be incorrect. INTRODUCTION Enzymes are proteins that allow a reaction to speed up. These proteins are made up of monomers known as amino acids.
Abstract This experiment showed that temperature, concentration and pH all affect the rate of enzyme reaction differently. Enzymes are very important in organisms and therefore understanding how and why they work the way they do in specific conditions is crucial. The results showed that an increase in temperature would also increase the reaction rate, until a temperature that was too high, where the enzymes began to denature and therefore the rate of reaction was slowed down. As concentration was increased, the reaction rate continued to increase.
Catechol oxidase is found in cell cytoplasm, their function in plants are to "help protect damaged plants bacterial and fungal disease." The objective of this experiment is to test the presences of catechol oxidase in various fruits and vegetables. Our group hypothesis states that, If catechol oxidase is present in the selected extracts, the null hypothesis is that catechol oxidase is not present in the selected extracts. Next, the prediction would be, if catechol oxidase doesn't differ with other enzyme sources, then the rates will
The objective of this lab was to determine the best pH level to increase enzyme activity. As this objective was met, it was discovered that water (pH level 7) was the best for percent absorbance. The hypothesis for this experiment was, “If peroxidase is an enzyme and therefore contains certain pH tolerances, then when placed in solution with pH levels of three, seven, and ten and the reaction is measured by a colorimeter, then water will be the optimal solution for maximum reaction rate.” As seen in the tables and graphs, the data supported the hypothesis due to the fact that most enzymes have an optimal pH of 4-9.
The 0.1% is the concentration amount. Just like temperature and pH, substrate concentration can speed the reaction only up to a certain limit. When we mixed pH 3 enzyme tube with substrate tube, we used 0.3 mL of hydrogen peroxide, but if we were to increase the amount, then the experiment would have been faster. Our
The null hypothesis, “There is no difference in the concentrations of NaHCO3 and the rate of photosynthetic activity.” is rejected. The alternative hypothesis is supported, that which the greater concentration of NaHCO3, the greater the rate of photosynthesis. Since it was found that the p-value was less than 0.05 in table 1 in all five treatments, this allows the null hypothesis to be rejected. This finding correlates with real life observations of faster rates of oxygen production during lab within the higher concentrations of
Methods of Data Collection Measuring the independent variable: The pH (the independent variable) is being tested on the turnip peroxidase to observe the reaction rates. 5 levels of pH are required for these series of reactions so pH buffers of 3, 5, 7, 9, and 11 are to be placed in each of the waters that will be put into the cuvettes for the experiment. Measuring the dependent variable: A colorimeter must be used in order to calculate the reaction rate/absorbance level of the turnip peroxidase when the different pH levels affect it. The colorimeter can be used to measure the transfer of heat to or from an object.
1.1 Abstract The purpose of quantitative analysis of protein using a spectrophotometer is to measure the concentration of proteins in a given sample. The experiment is conducted by laboratory method (Biuret Test) and using spectrophotometer to analyze the absorbance of reactants at 540 nm, hence determining the concentration of the proteins in a given sample. The purpose of stopped enzyme assay to study B-galactosidase is to determine the effect of temperature and concentrations of substrate on enzyme activity.
Introduction In class, a series of experiments were performed that pertained to the enzyme known as catalase, which converts hydrogen peroxide into oxygen. Due to peroxide being toxic to the tissues of both plants and animals, both possess the enzyme catalase, which breaks into two non-toxic compounds: water and oxygen gas. Enzymes are proteins that react to certain substrates to create a product, and continue doing so afterwards. Methods and Materials To test reactions between catalase and hydrogen peroxide, groups of three to four people were formed.
H20 + 2 O2 This experiment will use 1% catalase solution and 3% hydrogen peroxide solution, both diluted into water so the reaction slows down. Temperature will be controlled in this experiment to change the reaction speed of the enzyme and the substrate, this is what the experiment is looking at. The effect of the temperature will be determined by how much gas is released in two minutes, which will change the pressure inside the test tube and will be measured by a gas
The 3 concentrations of enzymes were 0.5 ml, 1.0 ml, and 2.0 ml of turnip extract, while the substrate consisted of 0.1ml, 0.2 ml, and 0.4 ml of hydrogen peroxide. In a separate tube, the control was made up of turnip extract and guaiacol, known as the color reagent. This was recorded the absorbance every 20 seconds for 3 minutes.