To investigate the effect of varying concentration of a certain sugar solution on the amount of osmotic activity between the solution and the potato chip.

Amy Grammer 11.6 AT1 Aim: - To investigate the effect of varying concentration of a certain sugar solution on the amount of osmotic activity between the solution and the potato chip. Background information If a dilute solution is separated from a concentrated solution by a partially permeable membrane, water diffuses across the membrane from the dilute to the concentrated solution. This is known as Osmosis. A partially permeable membrane is porous but allows water to pass through more rapidly than dissolved substances. Since a dilute solution contains, in effect, more water molecules than a concentrated solution, there is a diffusion gradient that favours the passage of water from the dilute to the concentrated solution. In living cells, the cell membrane is partially permeable and the cytoplasm and vacuole (in plant cells) contain dissolved substances. As a consequence, water tends to diffuse into cells by Osmosis if they are surrounded by a weak solution, e.g. fresh water. If the cells are surrounded by a stronger solution, e.g. salt water, the cells may lose water by Osmosis. Water Potential. The water potential of a solution is a measure of whether it is likely to lose or gain water molecules from another solution. A dilute solution, with its high proportion of free water molecules, is said to have higher water potential than a concentrated solution, because

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Osmosis Investigation

Osmosis Investigation Aim: To investigate the effect of varying concentration of a certain sugar solution on the amount of osmotic activity between the solution and a potato chip of a given size. Osmosis is defined as the net movement of water or any other solutions molecules from a region in which they are highly concentrated to a region in which they are less concentrated. This movement must take place across a partially permeable membrane such as a cell wall, which lets smaller molecules such as water through but does not allow bigger molecules to pass through. The molecules will continue to diffuse until the area in which the molecules are found reaches a state of equilibrium, meaning that the molecules are randomly distributed throughout an object, with no area having a higher or lower concentration than any other. Equipment list * Potato borer * Boiling tube rack * Boiling tubes * Paper towels * Weighing scales * Knife * Test tubes Prediction: For this particular investigation I think that the lower the concentration of the sugar solution in the test tube the larger the mass of the potato will be. This is because the water molecules pass from a high concentration, i.e. In the water itself, to a low concentration, i.e. In the potato chip. Therefore, the chips in higher water concentrations will have a larger mass than in higher sugar concentrations. When

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Investigate the effects of varying concentration of certain solutions on the amount of osmosis in a potato chip of a given size.

Osmosis in Plant Cells Plan: Aim To investigate the effects of varying concentration of certain solutions on the amount of osmosis in a potato chip of a given size. Prediction A definition of osmosis is: 'the movement of water molecules from an area of high water concentration to a low water concentration across a semi-permeable membrane' (Oxford dictionary 2000). In a high concentration of water the amount of solute (e.g. sugar) is low. These solutions are usually known as a dilute or weak solution. But in a low concentration of water the amount of solute (e.g. sugar) is high. These solutions are usually known as concentrated or strong solutions. When a weak solution and a strong solution are separated by a partially permeable membrane, the water will move from the area of high concentration to the area of low until both sides are equal. This is osmosis, and is shown in the diagram below. An Example of Osmosis Examples of osmosis can also be seen in living cells. Root hairs on plants take in water from the soil via osmosis. Water continuously moves along the cells of the root and up the xylem to the leaf. Water is moving to areas of lower water concentration all the time. This is shown in the diagram below. Example of Osmosis in a Root Hair Cell When a cell is placed in distilled water which is high water concentration water will move across the semi-

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  • Level: GCSE
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I want to find out if the concentration of the Hydrogen Peroxide affects the speed at which the potato gives off gas.

Catalase Investigation Aim: * I want to find out if the concentration of the Hydrogen Peroxide affects the speed at which the potato gives off gas. Planning Enzymes like catalase are protein molecules that are found in living cells. They are used to speed up reactions within the cell, and so are biological catalysts. Catalysts speed up reactions but they are not changed during the reaction. Enzymes only work on one specific type of substrate that means that there is only one kind of substrate that will fit into the enzyme's active site. Most enzymes optimum working temperature is 37°C (body temperature). Catalase is found in food such as potato that I will be using in my experiment. They are all very specific as each enzyme is used for different jobs. Catalase is used for removing Hydrogen Peroxide from the cells. Catalase is used to speed up the decomposition of the Hydrogen peroxide into water and oxygen. Preliminary experiment First of all I did a preliminary experiment, when we picked 15 potato chips at random and cut them down to the same length using a razor blade, making them even. I then set up the equipment as shown below and injected the hydrogen peroxide solution, and timed how long it took for 1ml of gas to be displaced as the H2O2 is attacked by the enzymes in the potato. ? Fig 1. Equipment setup To do this I will use the following: * * Potato

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  • Level: GCSE
  • Subject: Science
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In this investigation I intend to explore the one of the factors that affects the rate of reactions. My research from textbooks and the Internet suggests that this depends on several factors; temperature, pressure, pH and concentration.

In this investigation I intend to explore the one of the factors that affects the rate of reactions. My research from textbooks and the Internet suggests that this depends on several factors; temperature, pressure, pH and concentration. After research and careful consideration, in my experiment I am going to investigate how a change in temperature could affect the rate of reaction. Using the enzyme in potatoes (peroxidase) reacting with hydrogen peroxide. Rate of reaction increases by: * An increase in temperature * An increase in concentration * An increase in surface area * A catalyst increases the rate but doesn't take part in the reaction The collision theory is when particles of substances collide with each other and there is a reaction. The higher the temperature the more energy the particles have for a faster reaction, more likely that the enzymes/substrates with collide an lock. An increase in temperature increases reactions rates because there is more heat energy in the particles therefore the collisions happens faster. Enzymes work slower at low temperatures because the movement of particles is slower. Molecules have less energy to collide; enzymes and substrates don't find each other and lock. Each enzyme works most effectively at a certain temperature called the optimum temperature. Which is around 50?C, but over this temperature the enzyme rapidly

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Investigating the enzyme 'Catalase'

Year 11 Coursework: Investigating the enzyme 'Catalase' AIM To look at Hydrogen Peroxide (H2O2) being broken down into H2O and Oxygen (O2). We will also investigate the factors that change the rate of reaction. MATERIALS Scalpel White tile 30cm clear plastic ruler Test tubes & rack Stopclock 0ml measuring cylinder 2ml pipette H2O2 Cylinder of potato Goggles Cloth SAFETY The hydrogen peroxide is toxic, and is a bleaching agent therefore if it is spilled it must be cleaned up straight away. You must wear safety goggles to protect your eyes. The scalpel is dangerous, it is very sharp so you must not run and also be very careful while handling a scalpel. METHOD (pilot experiment) ) We will measure out the desired amount of H2O2 and pour it into a test tube 2) We mark and cut out the desired amount of potato with a scalpel. 3) Every 4 minutes we will measure the height of froth produced, to 1 decimal point, from the meniscus. 4) Record results 5) Plot a graph of results We will carry out a pilot experiment to find the best lengths of potato to use for the real experiment. FAIR TESTING To make this a fair test I will: * Monitor the room temperature * Use the same volume of H2O2 & same pH * Same batch/age/brand and freshness of potato * Same diameter of potato * Same ruler * Same person measuring each time, from the same level RATE OF REACTION If we

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To determine the water potential of a potato tuber cell using varying salt solution.

Aim To determine the water potential of a potato tuber cell using varying salt solution. Introduction Osmosis is the diffusion of water molecules from a region where it has higher water potential to a region where it has lower water potential through a partially permeable membrane1. As osmosis is a type of diffusion the same things that affect diffusion have an effect on osmosis some of theses things are: * The concentration gradient - the more the difference in molecules on one side of the membrane compared to the other, the greater the number of molecules passing through the membrane and therefore the faster the rate of diffusion2. * The surface area - the larger the area the quicker the rate of diffusion * The size of the diffusing particles - the smaller the particle the quicker the rate and polar molecules diffuse faster than non-polar ones3. * The temperature - the higher the temperature the more kinetic energy the particles have and so the faster they move. From the diagram4 we can see the process of osmosis in a simple expression. On the right side there is pure water, which has the maximum water potential of 0. Water potential is the pressure created by water. As you can see from the diagram the pure water is pushing its way through the semi permeable membrane at a high pressure. This is its water potential. Water potential is measured in kilopascals (kPa)

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Does the Concentration of CuSO4 Affect the Germination of Barley Seeds?

Does the Concentration of CuSO4 Affect the Germination of Barley Seeds? Investigation Analysis When looking at the data collection sheet it can be seen that as the concentration of CuSO4 increases, the percentage of seed germination decreases. This already shows a clear sign that enzyme inhibition has occurred. Looking at the "Average Length of Roots" graph, it can be seen that the concentration of CuSO4 does inhibit the growth of roots significantly because the average root length drops sharply after the 0% solution. However some of my results nay have been anomalous because the decline is far too steep to draw any reliable conclusions. When comparing this graph to the "Average Length of Shoot" graph, it can be seen that the average shoot length for each concentration depreciates at a steadier rate; perhaps then, heavy metal ions affect enzymes that are responsible for root growth more than they affect those that are responsible for shoot growth. This is could be a topic for further investigation. For both graphs however, its shows that the depreciation rate between each concentration decreases. For example, using the "Average Length of Roots" graph it can be seen that the gradient between each concentration becomes steadier and steadier as the concentration increases. This shows that inhibition of growth is affected most directly after the 0% concentration. When

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An experiment to show the progress of osmosis in potato tissues.

An experiment to show the progress of osmosis in potato tissues. Aim The aim of this coursework is to investigate the rate of osmosis in different concentrations of sugar solution using potato tissues. Prediction I think that in sugar solutions of high concentration, the mass of the potato will go down. This is due to the rules of Osmosis. Osmosis is the movement of water molecules across a partially permeable membrane, from a region of high water concentration to a region of low water concentration. There are two types of diffusion. These are: * Partially permeable membrane. This allows SOME particles to diffuse through things and not others. Most cell membranes are permeable to water. Diffusion of water through a partially permeable is 'The direction and rate of osmosis which depends on the differences in water concentration between the two sides of the membrane until equilibrium'. Only water molecules are small enough 2 diffuse through a partially permeable membrane. The tendency for water to move through a partially permeable membrane is described as its water potential and is at a maximum in pure water, if sugar is added to the solution, it lowers the water potential. The water potential depends on how much sugar solution is added. In high concentrations of water, the amount of sugar is low and in low concentrations of water, the amount of sugar is high. As the

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I predict that the stronger the solution (external) the more the potato chip will lose mass due to osmosis.

Osmosis - Plan Input Variable: Strength of water/sugar solution. Controlled: * Type of substance (in this case a potato chip). * Size of potato. * Conditions i.e. they are all in the same light and heat. * Volume of solution. Outcome: The change in length/mass of the chip. Prediction - I predict that the stronger the solution (external) the more the potato chip will lose mass due to osmosis. I have based my prediction on the theory of osmosis. When plant cells are placed in water, the water enters the cells. Each cell is surrounded by a cell membrane. It separates of the cell from the outside. The cell membrane has tiny holes in it. This allows small molecules to pass through but not large ones. The cell membrane is partially permeable. Osmosis is a special kind of diffusion to do with water molecules. It occurs when two solutions are separated by a partially permeable membrane. The stronger solution will absorb the molecules from the weaker solution. Therefore as the external solution Diagram Tin Foil H2O 5% 10% 20% 25% Salt Salt Salt Salt Apparatus > 5 Test Tubes; > 5 pairs of equal length potato chips; > Distilled Water; > 5%, 10%, 20%, 25% salt solutions (with water/ H2O); > Tin Foil; > Knife; > Ruler and Calculator. A fair Test Fair testing is an important part of this experiment and so to make sure the

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  • Level: GCSE
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