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Enzymes and their functions
Functions of enzymes in medicine and industries
Functions of enzymes in medicine and industries
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Recommended: Enzymes and their functions
Hydrolysis of Lipids Using an Enzyme Called ‘Lipase’
Research and Rationale
Enzymes
Enzymes are made up of proteins that are available in every cell of a living plant and animal [9] .Enzymes are very important for biochemical reactions. They act as catalysts and speed up biochemical reactions by using ‘an alternative reaction pathway of lower activation energy’ [5].Enzymes either starts a chemical reaction or allows it to occur faster [9]. Enzymes do not experience enduring changes therefore; remain unchanged at the end of the reaction [9]. Enzymes are very selective, they catalyse specific reactions. Their specificity depends on the shape of the enzyme. Enzymes consist of globular proteins and non-proteins [5].
In a reaction, two molecules must collide in the correct direction with adequate energy. This means that there should be enough energy in the reaction to allow the molecules to overcome the activation energy [5]. Activation energy (Ea) is the minimum energy that is needed in a reaction to trigger the molecules to a condition in which they can carry out a chemical reaction [6].
All Enzymes have an active site; this is the part of the enzyme where molecules with the right shape and functional groups bind to the enzyme [5]. The reacting molecule that binds to the enzyme is called the substrate [5]. Enzymes are known to have substrate specificity.
The route that is taken by an Enzyme when used in a reaction [5]:
There are two theories about enzymes carry out reactions called the ‘Lock and Key theory’ and the ‘Induced fit theory’.
Enzymes’ substarate specificty can be explained using the Lock and Key hypothesis[8]. This theory states that a specific substrate would only fit into an active site of an enzyme[9]. ...
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... the enzyme, as the shape of the lipase may be altered and the lipid molecules may not be able to bind to them and form a reaction. Therefore, I will ensure that the temperature is constant throughout the experiment to gain valid and reliable results with minimal anomalous results
On the other hand, I will manipulate the concentration of lipase being added to the solution. I will change the volume of lipase. I will have 6 different concentrations of lipids as I would carry out 6 different experiments to gather a wide range of data. I would use concentrations such as 0cm3, 2cm3, 3cm3, 4cm3, 5cm3 and 6cm3. I would have a control group where I wouldn’t use lipase to see whether the pH change occurs due lipase or bile salt emulsifying the fat. I would use a control group to allow me to see the changes that occur in lipids between adding lipase and not adding lipase.
The control for both curves was the beaker with 0% concentration of substrate, which produced no enzyme activity, as there were no substrate molecules for...
Equipment list: Test tubes were used to hold the milk, the lipase and the milk and lipase solutions. Test tube racks were used to hold the test tubes
An Investigation into the Effect of Lipase Concentration on the Hydrolysis Of Fats Using the data loggers a recording of the pH was taken every 5 seconds and for each experiment the data loggers produced graphs of the change in pH. From each of these graphs a gradient was calculated which showed the rate of pH change per second. Firstly I calculated the gradients by choosing the steepest section of the graph and dividing the change in pH of this section by the time. However this method proved to be quite inaccurate giving very varied results, for example in these results the average rate of reaction for the 4% lipase solution (-0.457 pH/min) was lower than the 3% lipase solution (-0.471 pH/min). Also the rates in the 2% lipase solution ranged from -0.01 pH/min to -0.95 pH/min showing little reliability in the results. This was partly as I was only guessing which the steepest part of the graph was.
Jim Clark. (2007). The effect of changing conditions in enzyme catalysis. Retrieved on March 6, 2001, from http://www.chemguide.co.uk/organicprops/aminoacids/enzymes2.html
its work. It is called the “lock and key” hypothesis. Lock in the enzymes. key: The substrate of the.
Alkaline Phosphatase (APase) is an important enzyme in pre-diagnostic treatments making it an intensely studied enzyme. In order to fully understand the biochemical properties of enzymes, a kinetic explanation is essential. The kinetic assessment allows for a mechanism on how the enzyme functions. The experiment performed outlines the kinetic assessment for the purification of APase, which was purified in latter experiments through the lysis of E.coli’s bacterial cell wall. This kinetic experiment exploits the catalytic process of APase; APase catalyzes a hydrolysis reaction to produce an inorganic phosphate and alcohol via an intermediate complex.1 Using the Michaelis-Menton model for kinetic characteristics, the kinetic values of APase were found by evaluating the enzymatic rate using a paranitrophenyl phosphate (PNPP) substrate. This model uses an equation to describe enzymatic rates, by relating the
Enzymes are biological catalysts - catalysts are substances that increase the rate of chemical reactions without being altered itself. Enzymes are also proteins that fold into complex shapes that allow smaller molecules to fit into them. The place where these substrate molecules fit is called the active site. The active site is the region of an enzyme where substrate molecules bind and undergo a chemical reaction. The active site consists of residues that form temporary bonds with the substrate and residues that catalyse a reaction of that substrate. (Clark, 2016)
Sequence of events when the union of a substrate with its enzyme occurs. Preliminary Work: Preliminary work was carried out to find a suitable range to collect data in a way that is appropriate. From the preliminary work I was able to determine suitable intervals of time to collect data. It showed that a volume of amylase below 4cm3 took a very long time to react thus making the experiment takes too long to do. From this I worked out that I should start.
The 'lock and key' hypothesis explains how enzymes only work with a specific substrate. The hypothesis presents the enzyme as the 'lock, and the specific substrate as 'key'. The active site binds the substrate, forms a product, which is then released. Diagram 1- a diagram showing the 'lock and key' mechanism works
Enzymes are types of proteins that work as a substance to help speed up a chemical reaction (Madar & Windelspecht, 104). There are three factors that help enzyme activity increase in speed. The three factors that speed up the activity of enzymes are concentration, an increase in temperature, and a preferred pH environment. Whether or not the reaction continues to move forward is not up to the enzyme, instead the reaction is dependent on a reaction’s free energy. These enzymatic reactions have reactants referred to as substrates. Enzymes do much more than create substrates; enzymes actually work with the substrate in a reaction (Madar &Windelspecht, 106). For reactions in a cell it is important that a specific enzyme is present during the process. For example, lactase must be able to collaborate with lactose in order to break it down (Madar & Windelspecht, 105).
Also changes in pH affect the charges on the amino acids. within the active site such that the enzyme will not be able to form. an enzyme substrate complex. The pH at which an enzyme catalyses a reaction at the maximum rate is called the optimum pH. This can vary considerably from pH 2 for pepsin. to pH 9 for pancreatic lipase.
Reactions occur when the particles of reactants collide together continuously. If they collide with sufficient energy, then they will react. The minimum amount of kinetic energy required for particles at the time of collision is called the activation energy and this theory is known as the ?collision theory?.
Enzymes act as catalysis to speed up a specific chemical reaction, due to their conformations. The shape of the enzyme is determined by the polypeptide sequence, because it causes the protein to fold into a native shape. This conformation creates a specific active site, which is comprised of a groove that a substrate can bind to (Cornish-Bowden, 1981). Competitive inhibitors can bind to the active site, preventing the binding of a normal substance and decrease the enzymes activity.
Collisions between reacting particles are therefore more likely to occur. All this can be understood better with a full understanding of the collision theory itself: For a reaction to occur particles have to collide with each other. Only a small percentage result in a reaction. This is due to the energy barrier that is overcoming.
Researchers experimented with enzyme activity with potato extract. Researchers will test enzyme activity by increasing and decreasing pH levels, lowering and increasing temperature, and substrate concentration effects. In the first experiment, researchers hypothesized that different pH levels would change how much Benzoquinone is created and how the enzymes function at neutral pH levels rather than higher and lower levels. Researchers used potato extract and different levels of pH to test their hypothesis. In addition, researchers questioned at what temperature does the greatest amount of potato extract enzyme activity take place in?