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Outline the role of enzymes as catalysts
Enzymes in biochemistry
Grade 10 biology. enzymes
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Recommended: Outline the role of enzymes as catalysts
In biology class, we were learning about enzymes. Enzymes are proteins that help catalyze chemical reactions in our bodies. In the lab, we were testing the relationship between the enzyme catalase and the rate of a chemical reaction. We predicted that if there was a higher percentage of enzyme concentration, then the rate of chemical reaction would increase or it would take less time. We placed 1 ml of hydrogen peroxide into four depressions. Underneath the first depression, we place 1 ml of 100% catalase and make 50% dilution with 0.5 ml of water. We take 50% of that solution and dilute with 0.5 ml of water and we repeat it two more times. there were four depressions filled with catalase: 100%, 50%, 25% , 12.5 % with the last three diluted …show more content…
This lab supported our hypothesis because the rate at which the paper discs rises tells us that enzyme concentration does have an effect on the timing of a chemical reaction. The six unifying principles prove that organisms have enzymes that speed up chemical reactions. At one point in time a certain common ancestor population didn’t have enzymes and some did. Thus it allowed for the advantaged to survive better and reproduce more. The offspring develop with the enzymes which their descendants will also have. The enzymes regulate by speeding up the chemical reaction so that the hydrogen peroxide won’t kill the cell(s). The hydrogen peroxide will enter the active site of the catalase and it will break apart into water and oxygen, which are …show more content…
We hypothesized that the more heat that we put in or the more heat that we take out, would denature the enzymes and slow down the rate. We set up a plate of depressions the same way as above. We boiled water to 50o C, poured the water onto a tray and did the steps of placing the discs in same as above and timed it until they rose above the surface. We did the same process but instead of using heat, we put ice and cold water on a tray which was about 3.5o C. The control for this experiment was the one that we did before because it was at room temperature. The results for the hot tray showed no rate. The cold tray sped up the rate of reactions making it occur faster than at room temperature starting at 6 for 100% catalase. This lab supported and disproved our hypotheses. It supported our hypothesis for adding more heat because the enzymes were in such hot conditions that the heat denatured the enzyme, making it not possible to create a chemical reaction. So the rate of reaction was zero because the enzymes didn’t split apart hydrogen peroxide. The cold tray disproved our hypothesis. We thought that the cold tray would also denature the the catalase so that there would be little to no rate. Maybe the data came out this way because the catalase was left out in room temperature for a long time that maybe when we took away the heat, it sped up the reaction rate.
This evidence alone suggests that higher increases in substrate concentration causes smaller and smaller increases in enzyme activity. As substrate concentration increases further, some substrate molecules may have to wait for an active site to become empty as they are already occupied with a substrate molecule. So, the rate of the reaction starts to level off resulting in a plateau in the graphs. This means that the reaction is already working at its maximum rate, and will continue working at that rate until all substrates are broken down. The only way the reaction rate would increase, is if more enzyme was added to the solution. This confirms that increases in substrate concentration above the optimum does not lead to greater enzyme activity. Therefore, the rate of reaction is in proportion to the substrate
For example, substrate concentration, enzyme concentration, and temperature could all be factors that affected the chemical reactions in our experiment. The concentration of substrate, in this case, would not have an affect on how the bovine liver catalase and the yeast would react. The reason why is because in both instances, the substrate (hydrogen peroxide) concentration was 1.5%. Therefore, the hydrogen peroxide would saturate the enzyme and produce the maximum rate of the chemical reaction. The other factor that could affect the rate of reaction is enzyme concentration. Evidently, higher concentrations of catalase in the bovine liver produced faster reactions, and the opposite occurs for lower concentrations of catalase. More enzymes in the catalase solution would collide with the hydrogen peroxide substrate. However, the yeast would react slower than the 400 U/mL solution, but faster than the 40 U/mL. Based on this evidence, I would conclude that the yeast has a higher enzyme concentration than 40 U/mL, but lower than 400
Catalase is a common enzyme that is produced in all living organisms. All living organisms are made up of cells and within the cells, enzymes function to increase the rate of chemical reactions. Enzymes function to create the same reactions using a lower amount of energy. The reactions of catalase play an important role to life, for example, it breaks down hydrogen peroxide into oxygen and water. Our group developed an experiment to test the rate of reaction of catalase in whole carrots and pinto beans with various concentrations of hydrogen peroxide. Almost all enzymes are proteins and proteins are made up of amino acids. The areas within an enzyme speed up the chemical reactions which are known as the active sites, and are also where the
The affects of pH, temperature, and salt concentration on the enzyme lactase were all expected to have an effect on enzymatic activity, compared to an untreated 25oC control. The reactions incubated at 37oC were hypothesized to increase the enzymatic activity, because it is normal human body temperature. This hypothesis was supported by the results. The reaction incubated to 60oC was expected to decrease the enzymatic activity, because it is much higher than normal body temperature, however this hypothesis was not supported. When incubated to 0oC, the reaction rate was hypothesized to decrease, and according to the results the hypothesis was supported. Both in low and high pH, the reaction rate was hypothesized to decrease, which was also supported by the results. Lastly, the reaction rate was hypothesized to decrease in a higher salt concentration, which was also supported by the results.
One of the most primitive actions known is the consumption of lactose, (milk), from the mother after birth. Mammals have an innate predisposition towards this consumption, as it is their main source of energy. Most mammals lose the ability to digest lactose shortly after their birth. The ability to digest lactose is determined by the presence of an enzyme called lactase, which is found in the lining of the small intestine. An enzyme is a small molecule or group of molecules that act as a catalyst (catalyst being defined as a molecule that binds to the original reactant and lowers the amount of energy needed to break apart the original molecule to obtain energy) in breaking apart the lactose molecule. In mammals, the lactase enzyme is present
The Effect of Changing the Concentration of the Enzyme Catalyst on the Rate of Reaction on Hydrogen Peroxide
This enzyme speeds up the break down of hydrogen peroxide into water and oxygen, as enzymes are biological catalysts. [IMAGE]The reaction: Hydrogen peroxide Water + Oxygen Catalase -------- [IMAGE] 2H2O2 2H2O + O2 Apparatus: Hydrogen Peroxide, Several sticks of celery, Stand, boss and clamp, 100ml conical flask, 25cm3 burette, 1800cm3 beaker, Rubber bung with delivery tube, Distilled water, Large container filled with water, 10cm3 measuring cylinder, 10cm3 syringe, 20cm3 syringe, Blender, Knife, Ceramic tile, Electronic balance (correct to 2 decimal places), Sieve, Stopwatch/timer. The variables: There are many possible variables in this investigation, such as pH, temperature, the concentration of substrate and the concentration of the enzyme.
At the time of conducting the experiment, the intention was to analyse the effect that an increase in catalase concentration had on the amount of oxygen (O2) produced if the hydrogen peroxide (H2O2) concentration was constant. It was proposed that when the catalase increases in concentration at the increments of 0.5%, 1%, 2%, and 4% and the hydrogen peroxide remained at a fixed concentration, the oxygen production would rise gradually. It was suggested that this would occur due to the collision theory ("BBC - GCSE Bitesize: Collision Theory") and the greater number of active sites thus an increase in accessibility allowing enzyme- substrate complex’s to be formed. According to the data gathered from the experiment, it can be implied that the hypothesis was supported as the data indicates an incline in oxygen
The dependent variable should be the height of the foam. The controls are the same volume of peroxide, the same concentration is the catalyse and of hydrogen peroxide and the same mass of liver. Catalyst explained Catalyst is a substance that increases the rate of a chemical reaction. It does this by reducing the activation energy, but which is left unchanged by the reaction. What affect does catalyse have?
Enzymes are biological catalysts, chemical reactions. Enzyme may act are called substrates and molecules called enzyme converts these into different products. Enzyme are used commercially, for example, synthesis of antibiotics. The study of enzyme is called enzymology.
Introduction / Background Information. This is an experiment to examine how the concentration of the substrate Hydrogen Peroxide (H2O2) affects the rate of reaction of the enzyme Catalase. In this experiment I will be using yeast as a source of catalase. Enzymes are catalysts which speed up specific reactions. Enzymes such as catalase are protein molecules, which speed up a specific reaction within the cell.
Materials used in the experiment included 5-7 g of the potato tissue, 50ml of 2.0M phosphate buffer coffee filter and guaiacol dye.
When the enzyme amylase comes in contact with the starch molecules, it decreases the energy needed for the chemical reaction that breaks starch down into maltose, a simple sugar. The maltose molecules, or substrate. Fit perfectly into the enzyme’s active site, and thus the activation energy is reduced and the reaction can take place. This won’t work, however, if the enzyme is denatured. Denaturing occurs when either the temperature or pH of the enzyme is changed.
the rate of reaction is greater than this range of temperatures had been exceeded (from around 35oC to 45oC) the rate of reaction has a rapid decline until the enzymes then become denature which is around 60oC. Results Table Temperature of water bath in oC. Minutes taken on 1st Experiment Minutes taken in Experiment Minutes taken in Experiment Average time taken Experiments 55 25 22 27 25
Abstract: Enzymes are catalysts therefore we can state that they work to start a reaction or speed it up. The chemical transformed due to the enzyme (catalase) is known as the substrate. In this lab the chemical used was hydrogen peroxide because it can be broken down by catalase. The substrate in this lab would be hydrogen peroxide and the enzymes used will be catalase which is found in both potatoes and liver. This substrate will fill the active sites on the enzyme and the reaction will vary based on the concentration of both and the different factors in the experiment. Students placed either liver or potatoes in test tubes with the substrate and observed them at different temperatures as well as with different concentrations of the substrate. Upon reviewing observations, it can be concluded that liver contains the greater amount of catalase as its rates of reaction were greater than that of the potato.