Investigation enzyme activity Essay Example

Investigation: enzyme activity Paper To investigate how the concentration of hydrogen peroxide effects the rate of reaction of an enzyme (catalase) Variables: These factors could effect the rate of reaction on an enzyme:   pH   Concentration   Temperature   Surface Area pH Enzymes function at different pH values. In neutral conditions the amount of oxygen gas given of in an enzyme-catalysed reaction will increase. An enzyme is affected by how much acid or alkali is present. Many enzymes work best in neutral conditions but some prefer acids and some prefer alkalis. This graph shows that the enzyme activity reacts best at pH7 (neutral). Concentration In concentrated solution there are more collisions between each particle, so the reaction occurs more quickly. This graph shows that increasing the concentration increases the enzyme activity. Temperature Reactions go faster as temperature rises. The rate of reaction also increases as the temperature rises, but with enzyme-catalysed reactions the reaction rate starts to decrease when the temperature is above 40 C. This is because enzymes are proteins and their structures start to damage above 40 C. This graph shows that the enzyme activity reacts best at 40? C as the enzyme starts to denature above 40? C Surface Area Reactions can react faster when solids are cut into smaller pieces. This is because there is more surface area which is exposed. The more surface area there is, the more collisions that take place between particles so the reaction rate is much quicker. This graph shows that small pieces react better than bigger pieces. Brief Outline I will test the effects of changing the level of concentration. For this variable I will use three different concentrations of hydrogen peroxide with catalase (enzyme). We will write a custom essay sample on Investigation: enzyme activity specifically for you for only $16.38 $13.9/page Order now We will write a custom essay sample on Investigation: enzyme activity specifically for you FOR ONLY $16.38 $13.9/page Hire Writer We will write a custom essay sample on Investigation: enzyme activity specifically for you FOR ONLY $16.38 $13.9/page Hire Writer I will change the concentration whilst keeping the time, concentration of catalase and the volume of hydrogen peroxide constant. I will begin all my tests at a constant temperature (room temperature) and I will repeat each test three times so I can obtain an average result. Background Knowledge: Lock and Key Model A catalyst is a substance which alters the rate of reaction without being used up. Enzymes are the catalysts in biological processes. They are large proteins that speed up chemical reactions. The enzyme forms the active site from small numbers of amino acids. The active site is the location on the enzyme where the substrate collides and the reaction takes place. If the shape of and the substrate do not match exactly then they do not bind. This makes sure that the enzyme does not work with the wrong reaction. Enzymes are not affected by the reaction, so when the products have been released, the enzyme is ready to bind with a new substrate. In my experiment the substrate was the hydrogen peroxide, the enzyme that we used was hydrogen peroxide and the product that was formed was oxygen and water. This can be explained by an equation: Enzyme + Substrate == Product In my experiment this is shown as: Catalase + H202 == H202 + 02 This equation explains how the catalase in our experiment binded with the H202 to break it down and form oxygen. Induced Fit Theory The induced fit theory states that the binding of a substrate to an enzyme causes a change in the shape of the enzyme. The enzyme and the substrate act on each other to affect the making of the active site to the usual complex between the enzyme and its substrate. As a result, this means the enzyme to catalyze a reaction has changed. This shows that enzymes are specific for specific substrates. I can tell that the catalase in my experiment is a suitable enzyme to break down the H202 as it will form oxygen as a product which is unharmful Denaturing Denaturing is the damage to the protein structure of an enzyme. Most enzymes react faster as the temperature increases. Enzymes also react at low temperatures, but when the temperature rises above 40 C their reaction rate start to decrease. This is because enzymes are proteins and their structures get damaged when the temperature rises above 40 C. When the protein is denatured it becomes less effective as a catalyst and soon the enzyme reaction gets slower and then finally it stops. This is why enzymes in washing powders which clean by breaking down grease and other stains, cannot be used with hot water above 40 C Activation Energy In order for a reaction too occur activation energy must be supplied. The activation energy is the energy required to start a chemical reaction. Some elements and compounds react together to bring themselves into contact. For others it is necessary to supply energy in order to start the reaction. This energy is the activation energy. Enzymes such as catalyst work by lowering the activation energy. The Kinetic Theory of Matter Everything is made of moving particles. The main points of the kinetic theory are: All matter is made up of small particles called molecules   The molecules are always vibrating   The higher the temperature, the faster the molecules are moving As the temperatures rises the particles get hotter. They have more energy and move around faster. Solid Liquid Gas Solid In a solid the particles are very close together and have very strong forces between them. Solid particles can only vibrate, this is why they cannot flow. Solids have a fixed shape and a fixed volume Liquid In a liquid the particles are a little further apart. The forces are not very strong. Liquids can flow and change shape but they always have a fixed volume. Gas In a gas the particles are further apart. There are no forces to hold all the particles together. Thy move about very quickly in the space they find. Gases can flow easily and change their shape and their volume depending on the container. Collision Theory The collision theory explains chemical reactions and the way in which the rate of reaction alters when the conditions alter. For a reaction to occur the reactant particles must collide. Only a fraction of the total collisions cause a chemical change. These are called fruitful collisions. The fruitful collisions have sufficient energy (activation energy) to break the existing bonds and to form new bonds, which then form the products of the reaction. Increasing the concentration of the reactants and raising the temperature make more collisions and therefore more fruitful collisions which increases the rate of reaction. All reactions involve two reactants which need collisions between them for particles to proceed. But not all collisions taking place between particles end up with a reaction. This is because in the middle of a reaction, there is a shape of the particle which is difficult to complete. This is called the transition state. The total kinetic energy of reactant molecules must be at least as high as the activation energy to be able to achieve the transition state, so the reaction can proceed. For a reaction to occur there must be successful collisions in which: 1) Particles must collide 2) Particles must have enough energy for the reaction to take place (activation energy). Which means the reaction must be successful If a collision between particles can produce sufficient energy and the particles collide fast enough in the right direction a reaction will take place. But not all collisions result in a reaction. A reaction is speeded up if the number of successful collisions are increased. The particles in a If the collision has If the collision does not liquid move around enough energy a have enough energy no continually reaction takes place reaction occurs The rate of reaction depends on how many successful collisions there are in a given unit of time. Surface area By breaking solids into smaller pieces the surface area is increased, which gives a greater area for collisions to take place. This causes an increase in the rate of reaction. Temperature.

Carbonate Compensation Depth (CCD)

Carbonate Compensation Depth (CCD) Carbonate Compensation Depth, abbreviated as CCD, refers to the specific depth of the ocean at which calcium carbonate minerals dissolve in the water quicker than they can accumulate. The bottom of the sea is covered with fine-grained sediment made of several different ingredients. You can find mineral particles from land and outer space, particles from hydrothermal black smokers and the remains of microscopic living organisms, otherwise known as plankton. Plankton are plants and animals so small that they float their whole lives until they die. Many plankton species build shells for themselves by chemically extracting mineral material,  either calcium carbonate (CaCO3) or silica (SiO2),  from the seawater. Carbonate compensation depth, of course, only refers to the former; more on silica later.   When CaCO3-shelled  organisms die, their skeletal remains begin sinking towards the bottom of the ocean. This creates a calcareous ooze that can,  under pressure from the overlying water, form limestone or chalk.  Not everything that sinks in the sea reaches the bottom, however, because the chemistry of ocean water changes with depth.   Surface water, where most plankton live, is safe for shells made from calcium carbonate, whether that compound takes the form of calcite or aragonite. These minerals are almost insoluble there. But the deep water is colder and under high pressure, and both of these physical factors increase the waters power to dissolve CaCO3. More important than these is a chemical factor, the level of carbon dioxide (CO2) in the water. Deep water collects CO2 because its made by deep-sea creatures, from bacteria to fish, as they eat the falling bodies of plankton and use them for food. High CO2 levels make the water more acidic. The depth where all three of these effects show their might, where CaCO3 starts to dissolve rapidly, is called the lysocline. As you go down through this depth, seafloor mud starts to lose its CaCO3 content- it is less and less calcareous. The depth at which CaCO3 completely disappears, where its sedimentation is equaled by its dissolution, is the compensation depth. A few details here: calcite resists dissolution a little better than aragonite, so the compensation depths are slightly different for the two minerals. As far as geology goes, the important thing is that CaCO3 disappears, so the deeper of the two, calcite compensation depth or CCD, is the significant one. CCD can sometimes mean carbonate compensation depth or even calcium carbonate compensation depth, but calcite is usually the safer choice on a final exam. Some studies do focus on aragonite, though, and they may use the abbreviation ACD for aragonite compensation depth. In todays oceans, the CCD is between 4 and 5 kilometers deep. It is deeper in places where new water from the surface can flush away the CO2-rich deep water, and shallower where lots of dead plankton build up the CO2. What it means for geology is that the presence or absence of CaCO3 in a rock- the degree to which it can be called limestone- can tell you something about where it spent its time as a sediment. Or conversely, the rises and falls in CaCO3 content as you go up or down section in a rock sequence can tell you something about changes in the ocean in the geologic past. We mentioned silica earlier, the other material that plankton use for their shells. There is no compensation depth for silica, although silica does dissolve to some extent with water depth. Silica-rich seafloor mud is what turns into chert. There are rarer plankton species that make their shells of celestite, or strontium sulfate (SrSO4). That mineral always dissolves immediately upon the death of the organism.

Business law Essay Example | Topics and Well Written Essays - 2250 words - 1

Business law - Essay Example bligation under a contract arises when two or more parties enter into an agreement with each or among each other and that agreement is entered into with a consideration or by Deed and no mistake, misrepresentation or frustration is attendant before, during or after the agreement. Under such kind of agreement the promisee is obliged to deliver and the promissor is entitled to receive in accordance with the terms of the contract and in the event of failure of the promisee to deliver what is expected of him, then the promissor is entitled to recover damages for breach of contract. 2 In the present case, Bajool freely entered into a contract with BSP with the terms of the contract clearly set forth in the agreement. The time of deliveries is specific as well as the manner and amount of payments in installment. Although there is always a probability that prices of any commodity may from time to time fluctuate, as in this case, Bajool did not negotiate for a provision at the time of the ag reement that would stipulate that in the event of a fluctuation, particularly a rise in the price of industrial salt, the agreed contract price shall forthwith also increase under a ‘rise and fall’ clause. Absent such a clause and considering that the contract is not long-term, Bajool is not justified in forcing BSP to agree to a different contract price and ultimately terminated the contract when the same failed. Therefore, Bajool’s termination of the contract is unwarranted and unjustified. This is especially true if the agreement of the parties had been put into writing considering that the Australian legal jurisdiction strictly adhere to the ‘parol evidence’ rule. This rule states to the effect that when the terms of an agreement are put into writing, then no other evidence of the intention and the terms that the parties agreed in the contract can be admitted to prove the terms agreed upon by them. This is the same doctrine held in the case of Me rcantile Bank of Sydney v