What effect does the pH have on the enzyme diastase? What effect does the temperature have on the activity of the enzyme diastase?

Problem: * What effect does the pH have on the enzyme diastase? * What effect does the temperature have on the activity of the enzyme diastase? Hypothesis: * The optimum pH for the diastase enzyme to work will be at 37oC. The temperature of 10oC and 20oC are going to show that they are too low for the enzyme to function while the temperature of 70oC will show that it is a too high for the enzyme to function in. * The optimum pH for the diastase enzyme will be 7. The pH of 1 and 3 will be too acidic while the pH of 10 will be alkaline for the enzyme. Purpose: * To determine the effect of pH and temperature on the enzyme activity Materials: * 1% starch solution * Lugol's iodine * Buffer solution * 0.2% diastase * 4 test tubes * 2 hot plates * Ice * 5 dropper pipettes * Spot plate * Thermometer Procedure: A . The 4 test tubes have been labeled with pH numbers 1, 3, 5, 10 2. To each test tube 2 ml of the diastase solution has been added, followed by 2 ml of the respective buffer 3. 4 drops of the starch solution was placed into a depression on the spot plate, followed by one drop of iodine. The change of color was recorded. 4. After 5 minutes, 2 ml of starch solution was added to each test tube and the contents were shaken 5. Immediately, 4 drops from each of the test tubes were placed into separate depressions on the spot plate that have been

  • Word count: 1831
  • Level: AS and A Level
  • Subject: Science
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Discuss mechanisms of viral persistence illustrating your answer with specific examples

Discuss mechanisms of viral persistence illustrating your answer with specific examples Viruses have acquired mechanisms to persist in human hosts even if antiviral drugs are applied to block significant stages in the virus cycle. Strategies are developed by viruses to 'evade, escape and survive' to fight against the host's immune system so that pathogens are able to persists and their purpose can be continued. Usually this type of strategy is employed by the 'hit and stay' viruses and their ultimate aim is to gain long residence in the host's body. Viral reservoirs represent a major problem with terminating infections as the drugs are no longer effective in virus clearance. This could lead to chronic infections, which can be divided into two kinds: The chronic persistent infection and viral latency. In the first type there is continuous replication of the virus from the time of the host being infected primarily and usually associated with virus evolution. The latter type of infection shows a long period of viral suppression as the viruses reduce their expression by displaying only a limited number of viral proteins. Another type of virus strategies are the 'hit and run' infections, which does not often cause persistence but continuous reoccurrence. The viruses are highly infective with the ability to escape to new hosts before the attack of the old infected host's immune

  • Word count: 1504
  • Level: AS and A Level
  • Subject: Science
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The effect of phosphate on cell division in root tips

The effect of phosphate on cell division in root tips In this investigation, my aim is to determine what the effect of phosphate ions are on plants that may be grown in a water culture, such as garlic cloves or broad bean seedlings. This can be determined by a root tip squash, examining the root tips under a microscope to see what percentage of cells have begun to undergo mitosis. A water culture is the growing of terrestrial plants with roots in an aerated solution*, where the concentration of difference ions can be altered to discover which are used for normal, healthy plant growth. In this case, I am able to change the concentration of phosphate ions to culture a batch of plants which can each be individually examined under a microscope. Mitosis is the nuclear division to produce two daughter nuclei containing identical sets of chromosomes, and with relevance to this experiment, takes place when an organism grows. There are four visible stages of mitosis - Prophase, Metaphase, Anaphase and Telophase. The final stage of cell division, which is not visible under a microscope, is Interphase, where the metabolic activity of the nucleus is intense. The nucleus is involved in protein synthesis, as well as chromosomes being replicated. Understandably, mitosis requires a great deal of energy to occur, and is supplied in the form of ATP. A root tip squash involves squashing,

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  • Level: AS and A Level
  • Subject: Science
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STEM CELL RESEARCH 'don't let his death be in vain' - Christopher Reeve.

GILL MOULD CHRISOPHER REEVE-'don't let his death be in vain' The actor Christopher Reeve has died of heart failure in hospital in New York on Sunday, at the age of 52. Reeve was one of the most famous supporters of stem cell research. Most of will not have even heard of stem cell research until Reeve began to champion its cause. Not only did Reeves battle paralysis but also the Bush administration which, he believed, had "dropped the ball" on stem-cell research - a form of technology, which could one day provide a cure for people with spinal injuries, like Reeve's What is a stem cell? It's been called "the most important cell ever discovered", because the stem cell can turn into any other cell in the body it is a "mother cell" with the ability to develop into different kinds of tissue. What's so remarkable about these cells is that they can be coaxed into becoming any cell in the body. They could potentially be used to treat such things as diabetes and heart disease. Imagine being able to grow replacement brain, muscle, and bone and organ tissue in the laboratory, which can be implanted into a patient without being rejected. Cardiac muscle destroyed by a heart attack could also be repaired. The same goes for brain tissue damaged by a stroke, and severed spinal cords. Paralysed victims of spinal injuries, such as Christopher Reeve, might have been able to walk again. More

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  • Level: AS and A Level
  • Subject: Science
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Discuss the ethical, social and economic benefits of the commercialand medical use of enzymes.

Discuss the ethical, social and economic benefits of the commercial and medical use of enzymes. This essay will be discussing the ethical, social and economic benefits of the commercial and medical use of enzymes. Firstly, an enzyme is a biological catalyst produced in cells, which is capable of speeding up reactions by reducing the activation energy for a reaction to take place. Enzymes are proteins that are highly specific due to its active site, which is formed by the specific folding of the tertiary structure of the protein. An area with a shape corresponding to the substrate molecule can react with the enzyme to be broken down into new products. The enzyme and the substrate bind together forming an enzyme-substrate complex that allows the reaction to take place after which the enzyme falls away unaltered with the products made. The type of enzyme used in industry can be extracellular or intracellular enzymes. Intracellular enzymes will be more expensive to use due to the high cost of the downstream processing, which needs to take place to isolate the enzyme. In addition, immobilised enzymes can be used which adds an extra cost as the enzyme is entrapped in a medium or on the surface of a matrix. There are various advantages of this, e.g. it does not contaminate the product thus making downstream processing cheaper, enzyme can be reused many times, which is

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  • Level: AS and A Level
  • Subject: Science
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The Ethics of Stem Cell Research.

The Ethics of Stem Cell Research Biology Amy Ng The Ethics of Stem Cell Research Since there is really no right or wrong in this world, it is not quite possible to tell if it is right or wrong for a patient to choose his principles and not take the stem cell operation. The patient can say, "Yes" or "No" according to their own thoughts and how successful will the operation will be. Stem Cells are blank cells that have not been differentiated yet and they are able to develop into cells of any kind in the human body. Researchers hope to use stem cells to repair tissues or renew and organ. There are three types of stem cells. They are the Totipotent, the Pluripotent, and the Multipotent. A Totipotent stem cell can develop into or generate a new organism or part. A Pluripotent stem cell can become any type of cells in the body, but they cannot grow into an entire organism. A multipotent stem cell can only become some types of cells. The first type of stem cells that was found was from human embryos, they seem to be the best way to treat the Parkinson's disease, he Alzheimer's disease, the juvenile diabetes, and etc, because they are totipotent stem cells. When the human embryos are 3-5 days old from the day that they were fertilized, the stem cells are extracted. They are then are placed in a dish, so they could be harvested to

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  • Level: AS and A Level
  • Subject: Science
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I'm aiming to work out the temperature which stops catalysts in the enzymes breaking down substances.

Biology Coursework: Enzymes Testing temperature on the effectiveness of enzymes Aim: I'm aiming to work out the temperature which stops catalysts in the enzymes breaking down substances. Hypothesis: I predict that temperature will have an effect on the effectiveness of the enzymes. I predict that to higher the temperature, the more likely the enzyme catalysts will stop breaking down the other substances. Background Information: There are two types of enzymes: Catabolic - Breakdown These are organic catalysis Anabolic - Build up that speed up the reaction without being broken down. Other enzymes include the digestive enzymes. There are three main types of digestive enzymes are: Lipase which converts fats into fatty acids and glycerol. Amylase which converts starch/carbohydrates into glucose. Protease which converts proteins into amino acids. There are two tests which you can perform to test for enzymes. These are the Benedicts' test which tests for sugars and the Iodine test which tests for starch. Enzymes are biological catalysts which control chemical reactions. Enzymes are shaped like proteins. The shape is held together by weak hydrogen bonds which can be disrupted by heat and pH specifics (breakdowns in different pHs). They also have a specific 'Active Site.' Heat, the surface area and the concentration can affect the

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  • Level: AS and A Level
  • Subject: Science
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"To see how concentration of a solution affects the enzyme activity."

Introduction/How does catalase work? Our brief for this experiment was; "To see how concentration of a solution affects the enzyme activity." To perform this practical experiment, we are going to use Hydrogen peroxide, and alginate (which is basically a yeast ball containing catalase, an enzyme). Enzymes exist in all living things. They are composed of polymers of amino acids and are produced in living cells. Each cell contains several hundred enzymes, which Catalase a vast number of chemical reactions. Enzymes are known as Biological Catalysts as they dramatically increase the rate at which reactions occur within living organisms, without being 'used up' or effecting the reaction in any other way. Enzymes catalysis saves the need for an increase in temperature in order to speed up reactions within living things. Such an increase in temperature would be lethal to the organism. Enzymes such as Catalase 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. Catalase is an enzyme found in food such as potato and liver. It is used for removing Hydrogen Peroxide from the cells. Catalase speeds up the decomposition of Hydrogen Peroxide into water and oxygen. It is able to speed up the decomposition of Hydrogen Peroxide because of the

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  • Level: AS and A Level
  • Subject: Science
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How does temperature effect respiration?

How does temperature effect respiration? Natalie Onions Joseph Whitaker School To investigate how temperature effects respiration, we would have to use something which contains living enzymes so that the limitations of which temperatures can be investigated are present. If enzymes are exposed to temperatures too far above or below their optimum range, they will denature and the experiment will be unsuccessful. (Nelson's Modular Science book). Equipment: Yeast solution (20gramms for each temperature) Beaker Water Scales Kettle Clamp stand Conical flask Gas syringe Sugar Spatula Measuring cylinder Thermometer Stopwatch Bubble wrap The Gas syringe was the most useful piece of equipment made available to us. A pipe is connected to a bung and placed on top of the conical flask. The other end was then connected to the gas syringe. The yeast will be respiring aerobically and so will be producing Carbon Dioxide gas. If the yeast should, for any reason, start to respire anaerobically, it will still produce carbon dioxide gas. This is the gas that we will be collecting. Any gas produced by the yeast solution in the flask travelled to the syringe and pushed the plunger upwards. This allowed us to take a very accurate reading of the amount of gas produced. The gas syringes are very expensive however and so we had to take great care with them during the

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  • Level: AS and A Level
  • Subject: Science
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An Investigation into the Optimum Temperature Amylase Will Work At.

Josef Nankivell 10L7 An Investigation into the Optimum Temperature Amylase Will Work At. Plan Aim: The aim of these series of experiments is to find out the optimum temperature at which the Enzyme, Amylase, will work most efficiently. Prediction: I predict that the optimum temperature that the amylase will work most efficiently at will be around 40°C. I think that this will be the optimum temperature because this is the optimum temperature that human amylase works at. I realise that my prediction could be wrong, as this may not be human amylase. Optimum After 40°c I predict that the reaction time will begin to gradually become slower until the amylase stops working altogether. I think this because after a certain temperature all enzymes begin to change shape, making them irreparable, no matter what the temperature is changed to after that. Prediction Cont' The Lock and key Method: Enzymes are shaped a certain way. Each type of enzyme is shaped differently, and each type is designed to fit with certain substrates (a substance that is being changed, in this case into soluble molecules.) The substrate and the Enzyme lock together and the enzyme will "break down" the substrate by splitting it up into smaller pieces, so it can be digested. Once an enzyme passes its "optimum temperature" it will begin to change shape, thus, making it unable to "break down" the substrate,

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  • Level: AS and A Level
  • Subject: Science
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