Investigating the effect of Temperature on the Cell Membrane of Beetroot Cells.

Investigating the effect of Temperature on the Cell Membrane of Beetroot Cells. To investigate whether temperature will damage and denature the plasma cell surface membrane of beetroot cells. Background Information. In spite of their many differences in function and appearance, all cells have a surrounding membrane (called the plasma membrane). The purpose of a cell membrane is to selectively control the movement of substances into and out of the cell. The membrane is made of 40% lipids, 0-10% carbohydrate and 50- 60% protein. Lipids tend to liquefy at high temperatures causing ruptures in the plasma membrane. In membranes there are intrinsic proteins that act as 'carriers' and channels that assist with movement of molecules through the membrane and extrinsic proteins that are embedded in the outer phospholipid layer acting as receptors. Proteins inside the cytoplasm are found in the ribosomes, rough endoplasmic reticulum and golgi vesicles. Proteins in plants are more likely to withstand higher temperatures of 50 oC, but once proteins have denatured they are no longer able to carry out there function. The membrane is an extremely thin partially permeable 7.5 (nm) layer. Lipids belong to a group known as triglycerides that are made by the combination of three fatty acid molecules chemically linked to one glycerol molecule. All cells have a surrounding membrane is some

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  • Level: AS and A Level
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Investigating the effect of temperature on the enzyme amylase.

Investigating the effect of temperature on the enzyme amylase. Prediction. My prediction for this experiment is that as the temperature is increased the time taken for the starch will decrease until a certain point where the time will start to increase. Therefore the rate will increase until a certain point and then will start to decrease. The reason for this being at enzymes work best at a certain temperature from around 35 to 40^0C. The higher the temperature the faster the enzymes will become denatured this is because enzymes are proteins; therefore an increase in temperature will cause an irreversible change in the shape of the molecule, meaning the enzyme is denatured. Moreover, during the five minutes that the amylase enzyme is at the high temperature the faster the enzyme will become denatured. However, the enzymes will not become denatured at a low temperature but enzymes will not work as fast as they would around 35/40^oC. So as the temperature starts to increase the time of the reaction will de crease until a certain point where the time will increase. So in the terms of rate enzyme will work faster until a point where the temperature gets to high and they stop working as fast or all together. Results. Temperature (^0C)^ Time taken for starch to be broken down. (Minutes) First time. Second time (Minutes) Average time (minutes) Rate of

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  • Level: AS and A Level
  • Subject: Science
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Investigating the effect of temperature on the enzyme amylase.

Biology coursework - Investigating the effect of temperature on the enzyme amylase Introduction Enzymes are vital; they control and catalyse all of the chemical reactions inside living cells. The enzymes speed up reactions, which would not otherwise happen rapidly enough to maintain the essential life processes. Amylase is the enzyme found in our Saliva. It is a catalyst, which works by breaking down substrate into smaller pieces: increasing the surface area, allowing the enzyme to work on the starch quicker and therefore speeding up the reaction. The aim of this experiment is to see how temperature affects the amylase and its ability to effectively break down starch and form maltose. I will be investigating at which temperature the enzyme becomes irreversibly de-natured and at which temperature it becomes inactive. Starch mixed with water on its own reacts very slowly, taking years too react but because we have the enzyme amylase in our saliva the enzymes catalyses the reaction so well that it can break down starch into sugar in minutes or seconds. Variables The variables in the experiment will be the temperature of the saliva and starch solution, the time at which I record the results, the pH of the starch solution and saliva and the quantities of the solutions. The temperature will be the manipulated, Independent variable as this is what I will be changing. The

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See how different concentrations of yeast affects how much oxygen is given off in 1 minute, when 10cm3 of yeast (which contains catalyse) is mixed with 10cm3 of hydrogen peroxide.

Catalase is an enzyme found in all living cells. It makes Hydrogen Peroxide decompose into water and oxygen. You can represent this in the equation: 2H2O2 =2H2O + O2 Enzymes: Enzymes are able to increase the rate of reaction without actually being consumed in the process. In all, enzymes are very efficient. Small quantities at low temperatures are able to produce results, which would require high temperatures and a violent reaction from any normal chemical means. Although increases in temperature may speed up the reaction, enzymes are unstable when heated. There are three important definitions that are used when talking about enzymes: - The substance that enzymes act on is the substrate. The substance formed by the reaction is the product The site on which the enzyme takes place is called the active site. Enzyme function can be explained by the Lock and Key Hypothesis: the active site of an enzyme (the lock) has a specific shape in which only the precise amount of substrate (the key) will fit - forming an enzyme-substrate complex. Therefore producing a product. All enzymes have the following 4 properties: · All enzymes are proteins · Enzymes are catalysts · Enzymes are denatured by high temperatures · Enzymes work best at a certain pH (normally 7) The Effect of Enzyme concentration: As long as the concentration of the substrate is much

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  • Level: AS and A Level
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Pros and Cons of Genetic Engineering

Pros and Cons of Genetic Engineering Introduction The first step to understanding genetic engineering and embracing its possibilities for society is to obtain a rough knowledge base of its history and method. The basis for altering the evolutionary process is dependant on the understanding of how individuals pass on characteristics to their offspring. Genetics achieved its first foothold on the secrets of nature's evolutionary process when an Austrian monk named Gregor Mendel developed the first "laws of heredity." Using these laws, scientists studied the characteristics of organisms for most of the next one hundred years following Mendel's discovery. These early studies concluded that each organism has two sets of character determinants, or genes. For instance, in regards to eye colour, a child could receive one set of genes from his or her father that were encoded one blue, and the other brown. The same child could also receive two brown genes from his or her mother. The conclusion for this inheritance would be the child has a three in four chance of having brown eyes, and a one in four chance of having blue. Genes are transmitted through chromosomes which reside in the nucleus of every living organism's cells. Each chromosome is made up of fine strands of deoxyribonucleic acid, or DNA. The information carried on the DNA determines the cells function within the organism.

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The Renal System.

The Renal System: The renal system consists of the bladder, kidneys (the kidneys are approximately eleven-cm long, six cm wide and four cm thick), urethra and the ureters. The kidneys are placed under the bottom of the rib cage and close to the spine. There are two functions of the renal system; these are to get rid of waste materials and to control the level of water in the body. Waste materials are removed from the blood and pass out through the body during the process of excreting urine. The levels of water in the body are controlled to ensure that the concentrations of different liquids within the body are kept within safety limits. This process is called osmoregulation. The kidney's function within the body is to clean the blood and get rid of anything the body doesn't want or need or that is harmful to its self. There is a large amount of space in the kidneys. People can not only survive with one kidney but also lead very healthy, active lives if they choose to do so. If a person is unfortunate to suffer from complete kidney failure, the blood allows waste materials to build up within the body as a result the levels of toxicity in the body rises. The body will eventually become poisoned internally if the kidneys can't clean the blood. Urea is produced in the liver; it is white in colour and is a crystalline substance. As the body doesn't store protein instead it

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  • Level: AS and A Level
  • Subject: Science
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"To Clone or Not to Clone- That is the Question".

One World Essay "To Clone or Not to Clone- That is the Question" For years and years, the cloning of living beings has just been an aspect of science fiction. Although several movies have been created based on human cloning as such, their scientific accuracy has made the general public dismiss them as something not capable of in the near future. When the first ever living clone of a six-year-old sheep was created (to the right), the world was in an uproar. Dolly, the sheep clone named after singer Dolly Parton, had been cloned from the udder cell of an adult ewe by a group of scientists in Scotland. People realized that this breakthrough could be a door to unimaginable technology, not necessarily positive. The notion that this discovery could change the world and lives was beginning to threaten the minds of activists and others. Many of the fears that come with these theories are within cultural and religious beliefs, or from being exposed to too many movies. Films of human cloning depict terrible things that happen to those that tamper with nature. A very famous example of this is Mary Shelley's tale of Frankenstein. Even through historic cases, such as where Nazi doctor Joseph Mengele flees to Brazil after the crash of the Nazi rule and World War II and attempts to use Hitler's tissue to create several more Hitlers, people have wondered whether it was truly possible. When

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The rate of respiration in yeast and how it is affected by temperature.

The rate of respiration in yeast and how it is affected by temperature. Science Biology: Planning For my coursework I am going to investigate how temperature can change the rate of respiration on yeast. I shall do this by conducting an experiment which will involve the timing of the yeast, water and glucose. I shall time how long it takes for the yeast mixture to respire 10 bubbles. I have chosen yeast because it responds quite quickly so it doesn't take all day. When I chose yeast I was aware of the factors that will affect enzymes and living things. These are: * Temperature * Oxygen availability * Glucose availability * PH * Radiation (Not in my experiment) * Water * Concentration Preliminary Work I discovered that the PH in the experiment denatures the enzyme as do other enzymes and temperature. Anaerobic respiration is the production of carbon dioxide without the use of oxygen. So all living things need oxygen to aerobically respire and yeast is a living thing. As yeast aerobically respires it produces ethanol which gives us the smell of the alcohol. I am using glucose because it reacts with yeast. The preliminary experiment showed that as the concentration of the water and yeast solution to the fixed amount of glucose increases the rate of reaction and therefore produces more carbon dioxide, we measured this in how long 10 bubbles took to come out of the

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  • Level: AS and A Level
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What Makes An Oil Runny?

What Makes An Oil Runny? Planning Apparatus Method We set up the apparatus as above. We then filled the capillary tube with oil. We then put a small ball bearing in to the tube and used a magnet to pull the ball bearing to the 22cm mark and checked the room temperature. We allowed the ball bearing to fall through the oil by removing the magnet. The person removing the magnet would count down in order for the person timing to be able to tine the experiment more accurately. We decided to take 7 readings and use only the five readings closest to each other and that were anomalies we repeated, so that on the whole we had a more accurate set of results. To make the experiment safe we all wore safety goggles and were careful not to expose the oil to a naked flame. We also ensured that we didn't get Hypothesis My hypothesis is that a body passes through a thick oil more slowly than a thin oil. Therefore the larger molecules are the less runny or more viscous. To support this theory I give the following examples C8H18 is a liquid and C32H68 is a solid. This helps to support my theory because the structure of the C32H68 is the same, just longer than C8H18 so the longer molecule of C32H68 is tangled like a piece of spaghetti and it is so tangled that it can't move and this makes it a solid the same idea works for the viscosity of the alkane liquids we tested in our experiment

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  • Level: AS and A Level
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Whats involved in Homeostasis.

Homeostasis Homeostasis is involved in keeping the body's internal environment constant (like the thermostat of a central heating system). Homeostasis keeps the body's temperature at a certain level (36.5oC) and it keeps the pH of the body at a certain level so that enzymes don't denature. Blood glucose is kept constant, CO2 levels and O2 levels are monitored to ensure that enough oxygen and not too much carbon dioxide are in the blood. The overall concentration and volume of blood is also monitored homeostatically. Cannon first used the term Homeostasis in the late 1920s. Homeostasis is very important to animals because it allows them to rely on the external environment. A constant internal environment allows a considerable degree of independence and allows animals to live in areas from the arctic to the tropics. Many of the mechanisms involved rely on negative feedback. A movement from the set level (e.g. a rise or fall in body temperature) is detected by receptors. These receptors then send information to the control centre in the brain which reacts by returning to the original value. For example, the temperature control mechanism. Humans maintain body temperature within 1oC of 36.5. If the temperature rises too high, the resulting increase in blood temperature is detected by receptors in the hypothalamus in the brain. The heat loss centre also in the hypothalamus sends

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  • Level: AS and A Level
  • Subject: Science
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