Properties of Hydrocarbons - To find out how the flammability and thickness of oil products changes with boiling point.

Properties of Hydrocarbons Aim - To find out how the flammability and thickness of oil products changes with boiling point. * Equipment/ The equipment utilised in this experiemnt will be: . A heat proof mat to place on the surface to stop any spillage. 2. Some books will be required, just one or two would be necessary to prop up the slide to create a slope. 3. A slide for the oil to slide down, simply once a drop is placed at the top it will slide downward and be timed in it's speed. 4. Lastly a stopwatch to time the experiment. * Method/ This experiment will be conducted fairly simply; firstly, we must place the heat proof mat on the surface in use, then stack one or two fairly thick textbooks for a good height to be used as aslope. The slide itself will be a literal slide. With this in place we then get the oil in question [5 used in this experiment] we then very carefully release one drop of oil and begin timing it. It will then slide down the slide and once it hits the heat proof mat we then stop the stop watch, and record the time, after doing this for the first oil, we need to thorooughly wash and dry the slide and repeat it for the other 4 oils. * Fair Test/ In order for me to obtain the most fair and unbiased results possible, not to mention the most accurate and factual, I have to make sure the test is performed unbiasedly and fair in every field. I have

  • Word count: 697
  • Level: AS and A Level
  • Subject: Science
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Best method for determining silver ions in solution

Chemistry Coursework Aim I am going to investigate which is the best method for determining silver ions in solution. I am interested to see whatever a electrode potential method or a chemical method (e.g. titration) is more appropriate, especially at low concentration. Background Information Redox If we consider the following reaction: 2Na(s) + Cl2(g) --> 2Na-Cl+(s) Salt (Sodium Chloride) is formed when Sodium is added to Chlorine gas. Sodium Chloride is an ionic compound, which is made up of Na+ and Cl- ions. The difference between Na(s) and Na+(s) is that an electron is removed from the Na atom and this a positive charge formed as the number of protons, which are positively charge is not equal to the negatively charged electron. But NaCl(s) is not charged overall, so where is the electron gone? If we look at the equation more closely, we can split the reaction into two parts, and this is called half equations: 2Na(s) --> 2Na+(s) + 2e- Cl2(g) + 2e- --> 2Cl-(s) The first equation shows that each sodium atom lost one electron and formed a Sodium ion and an electron. While each chlorine atom gained an electron and form Chloride ions. These two equation is balance and overall there is no electron lose as once a sodium has given up its electron, a chlorine atom will form an ion with this electron. We called this type of reaction Redox - Reduction and Oxidation. The sodium

  • Word count: 3792
  • Level: AS and A Level
  • Subject: Science
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A primary role for the glucose molecule is to act as a source of energy; a fuel

A primary role for the glucose molecule is to act as a source of energy; a fuel. Plants and animals use glucose as a soluble, easily distributed form of chemical energy which can be 'burnt' in the cytoplasm and mitochondria to release carbon dioxide, water and energy. This energy is then trapped in the ATP molecule and used for everything from muscle contraction to pumping water across cell membranes. Single sugar molecules can also be attached to proteins and lipids to modify their biological role as enzymes, signaling molecules and as components of membranes. Very often the addition of one or more sugar molecules will make the recipient molecule more soluble. Glucose (and other monosaccharides) are very hydrophilic ("water loving"), and this can be a problem. Pure monosaccharides, such as glucose, attract water. Any plant (or animal) that tried to store large amounts of glucose would have a serious problem with osmosis. Cells containing large numbers of glucose molecules would be constantly fighting the incessant movement of water from the outside of the cell to the inside. The osmotic pressure would be so great that even behind their protective walls, plant cells would have difficulty functioning. One way round this problem is to convert the monosaccharides to polysaccharides. These larger molecules do not have such a great osmotic pressure and hence can be stored with

  • Word count: 856
  • Level: AS and A Level
  • Subject: Science
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Effects of Copper Sulphate on the Activity of Catalase

Effects of Copper Sulphate on the Activity of Catalase Introduction Enzymes are biological catalysts and their contribution to our existence is pivotal. Without them, human and animal digestion may take days. Enzymes therefore, help catalyse reactions at an increased metabolic rate. Each type of enzyme would normally act upon only one type of substrate molecule. This is due to the specific shape of the active site. Sometimes, enzyme activity is disrupted not because of temperature or other environmental factor but by alien molecules, which attach themselves to the enzyme molecules just as easily as the intended substrate. This is called inhibition. Aim I will be testing the effects of Copper Sulphate (inhibitor) on a reaction between catalase and hydrogen peroxide. I predict that the greater the concentration of the copper sulphate, the slower the reaction. Reactions will be measured at the rate of which oxygen is released from the H2O2. I will use yeast as a source of the enzyme catalase. If it is an inhibitor, I will go further and try to prove if it is a competitive or non-competitive by increasing substrate concentrations. Fig 1 shows word equation of the reaction. 2H2O2 2H2O + O2 Figure 1 Scientific Involvement At a molecule level, it is thought that the substrate molecules fit precisely into the enzyme molecules in the same way that a key fits a lock (see

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  • Level: AS and A Level
  • Subject: Science
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The enzyme amylase digests starch to form sugar.Amylase is released in the mouth and carries out the reaction at body temperature 37 degrees centigrade.

The enzyme amylase digests starch to form sugar.Amylase is released in the mouth and carries out the reaction at body temperature 37 degrees centigrade.I will investigate the effects of temperatures higher and lower than room temperature on the rate of this reaction. Prediction I think that the reaction will be fastest at 50 degrees centigrade ,because at body temperature reactions are carried out quickly but at a higher temperaturem the enzyme and sugar particles will move faster due to a larger amount of heat energy,the two substances will collide more often therefore ,more reactoins.I believe that the reactions willbe slowest at 60 degrees centigrade. During extremes of temperatures,the active site of an enzyme changes ,the substrase will not be able to react with the enzyme because enzymes are specific(only react with certain shape substrase). The active site would become denatured resulting in less reactions causingg the rate of digestion to fall. The enzyme has an active site that helps it to recognise its substrase in a very specific way. Just like a key that only fits into a certain lock , each enzyme has its own specific substrase.This is called the lock and key theory,the diagram below shows this. The digestion of carbohydrates is performed by various enzymes. Amylase, found in saliva and in the intestine, breaks starch, dextrin, and glycogen into maltose,

  • Word count: 750
  • Level: AS and A Level
  • Subject: Science
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Control of internal environment of living organisms.

Control of internal environment of living organisms. It is very important that the internal environment of living organisms is kept constant, as the cells inside the body need this constant environment to work efficiently, failure to do so could result in death. Therefore no matter what is happening in the external environment homeostasis keeps the environment around the cells the same. Examples of things that are controlled are respiratory gases (oxygen and carbon dioxide), pH, the concentration of nutrients and waste products, the concentration of salts and other small ions, the volume and pressure of blood plasma and temperature (humans sweat to lower body temperature). This regulation is called homeostasis (staying the same). Most of the body's homeostatic systems rely on negative feedback systems to resist change. In these systems there needs to be a detector which can measure the value that needs to be controlled. When the detector finds that the value is higher then should be it sends information to an effector which will then correct the level. This happens till the detector finds the value is too low and the effector then changes what it is doing so the value then rises. Information is therefore feed back to the detector from the effector, the feedback is called negative due to it stopping the effector doing one thing and stimulating it to do the opposite. As there

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  • Level: AS and A Level
  • Subject: Science
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Investigation: To find the effect of the concentration amylase on the rate of breakdown of starch

. Investigation: To find the effect of the concentration amylase on the rate of breakdown of starch. PREDICTION The lower the concentration of amylase, the slower the breakdown of starch will be. If you double the amount of amylase, the breakdown of starch will be quicker because there are twice as many active sites. I expect to see a graph like: Rate of Breakdown Concentration of amylase RESEARCH Enzymes are made of long protein molecules, which are folded up so they have an irregular globular shape. One part of the surface is the active site and fits exactly into the substrates, which then reacts. When a substrate molecule collides with an enzyme it becomes attached to the active site of the enzyme and the reaction then takes place. The products then leave the active site, which can be used again. Temperature effects the efficiency of the enzymes. The higher the heat the greater the proportion of damage on the enzyme. The enzyme will no longer fit in the active site. Below normal temperatures, enzymes become less and less active, due to reductions in speed of molecular movement, but this is reversible, so enzymes work effectively when returned to normal temperature. In digestion the substance which is present at the beginning of the experiment is called the substrate. The substance made at the end of the reaction is called the product. For example, in

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  • Level: AS and A Level
  • Subject: Science
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Investigate the effect of temperature on the action of rennin and milk.

Investigate the effect of temperature on the action of rennin and milk Rennin is an enzyme produced in the stomach of young mammals. It speeds up the reaction that makes milk proteins go solid. I am going to find out what is the best temperature that rennin works at I think that the rennin will work best at a temperature of 40 I think this will happen because most enzymes work best at a temperature of 37 (body temperature ) but the rate of reaction doubles if the temperature is 10 higher so the enzyme works best at 47 and I have rounded this down to 40 this is because the temperature 47 would be to hard to get on the thermometer and also if I would round this up to o50 the enzyme would stop working because it would become denatured this is because rennin is a protein. I think below this temperature the rennin will work slower this is because the enzyme is a protein and proteins need a high temperature to work. I think that above 50 the rennin will denature this is because the rennin is a protein and proteins can not work at a temperature that is too high. (50 being too high) This is backed up by a simulation I did on the computer to show an experiment investigating the effect of temperature on amylase. These are the results which I got: Temperature Time 0 Didn't breakdown 20 1 mins 30 6 mins 40 5 mins 50 6 mins 60 Didn't breakdown These results back up my

  • Word count: 829
  • Level: AS and A Level
  • Subject: Science
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The effect of amylase concentration on the breakdown of starch

The effect of amylase concentration on the breakdown of starch This Essay was awarded a mark of A, so they say. Only the plan is included For this investigation I am going to investigate the effect of the concentration of an enzyme, in this case Amylase, on the time taken for the enzyme to fully breakdown the substrate, which in this case is starch. The reason why these two enzymes have to be used is because each enzyme is designed specifically to break down only one substrate as each enzyme is made of a protein that causes it to be a specific shape, in this case the enzyme Amylase can only break down starch to dextrin. I am going to do this by planning an experiment, carrying out the experiment, recording any relevant results and plotting graphs from which I will be able, hopefully to gain a strong conclusion. I will finally evaluate the whole investigation. Before the experiments start we will be given a bottle containing a 1% solution of starch and another bottle containing a 1% solution of the enzyme Amylase. From these bottles I will be able to take out as much of either solution as I wish. I cannot start he experiment until I know which factors I am going to change and which I am going to keep constant. Because the thing I am trying to test in the effect of the concentration of the enzyme, the only thing that I should be changing in each experiment is the

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  • Word count: 2298
  • Level: AS and A Level
  • Subject: Science
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Rate of catalase activity.

Enzymes such as catalyse are protein molecules, which are found in living cells. They are used to speed up specific reactions in the cells. They are all very specific as each enzyme just performs one particular reaction. Catalyse is an enzyme found in food such as potato and liver. It is used for removing Hydrogen Peroxide from the cells. Catalyse reacts to decomposition Hydrogen Peroxide into water and oxygen. It is able to speed up the decomposition of Hydrogen Peroxide because it reacts with the Hydrogen Peroxide molecule. This type of reaction where a molecule is broken down into smaller pieces is called an anabolic reaction. I will be investigating how temperature effects the rate of catalyse activity. To do this I will be adding liver (Catalyse) to hydrogen peroxide at different temperatures and measuring the oxygen given off against the time. I believe that the longer the liver is left in the hydrogen peroxide solution the greater the reaction and the more oxygen will be released. I think at first the reaction will be rapid but as time goes on the reaction will slow down. This is because the hydrogen peroxide will start to be used up and there will be less hydrogen particles to collide and therefore less oxygen will be produced. I think that at body temperature (370C) the reaction will take place the fastest as the enzyme is working at the temperature it normally

  • Word count: 1296
  • Level: AS and A Level
  • Subject: Science
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