To investigate the effect of varying concentration of glucose solutions on the osmotic activity between the solution and potato slices.
INVESTIGATING OSMOSIS IN PLANT CELLS AIM: To investigate the effect of varying concentration of glucose solutions on the osmotic activity between the solution and potato slices. SCIENTIFIC THEORY: Osmosis is defined as the net movement of water molecules from a region of high concentration to a region of low concentration of water, through a partially permeable membrane, which only lets smaller molecules through. This can also be described as movement down the concentration gradient. The molecules continue to diffuse through the membrane until both sides reach a state of equilibrium. This is also known as the isotonic point when the molecules are equally distributed on both sides of the membrane so that no one area has a higher or lower concentration than the other. Plant cells have a strong cell wall and a partially permeable cell membrane around them. When cells are surrounded by a solution more dilute than their own, (hypotonic solution-with more water than solute molecules), the cell swells up and becomes "turgid". This is because the water molecules diffuse from the solution to the plant to equal out the concentration levels. The strong cell wall prevents them from bursting. Figure 1- A turgid plant cells in more dilute surroundings (from "Biological Sciences Review") When they are surrounded by a solution more concentrated than their own, (hypertonic- less
Investigation to see what effect different concentrations of solution has on osmosis
INVESTIGATION TO SEE WHAT EFFECT DIFFERENT CONCENTRATIONS OF SOLUTION HAS ON 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. Aim The aim of the experiment is to investigate what effect different concentrations of solution has on osmosis. Prediction I think that in a more concentrated solution of molar, the potatoe chip will lose more weight, than in a solution less concentrated. In pure water, the potatoes will swell due to water entering their cells by osmosis. However, in rich sugar solution i.e 1 Molar, the potatoe chip will shrink as water is leaving thwe cells by osmosis. Test tube 1, will be for sugar solution, test tube 2 for 0.5 Molar and test tube 3 for pure water solution i.e 0.0 Molar. Apparatus * Test tubes (x3) * Measuring Cylinder * A stop watch * Sieve * Potatoe chips * Weighing scale * Ruler * Knife Fair Test For the results to be the most accurate and reliable they can, I will repeat the experiment four times. For the investigation to be a fair test, the following should and will be considered: * The pieces of potato must be the same width and length, as they must have the same surface area given to the solutions. This means that if one cylinder is given more solution than another cylinder, then the one with the larger
To investigate the effect of osmosis.
Osmosis Investigation Planning Experimental Procedures Aim To investigate the effect of osmosis. Background Research In order to attain a working knowledge of osmosis and its effects, I looked through school textbooks together with some information I had obtained at the library. Many substances pass in an out of cells by diffusion. Diffusion is the movement of particles from a region where they are at a higher concentration to a region where they are at a lower concentration. This process does not require energy from respiration. An example of this is the way cells take up oxygen and get rid of carbon dioxide: The greater the difference in concentration betIen the two regions, the faster the rate of diffusion. Small particles also diffuse faster than larger particles. Water passes in and out of cells by a type of diffusion, called osmosis. Osmosis is the diffusion of water in plants, from a dilute solution to a more concentrated solution, across a partially permeable membrane; or from a high concentration to a lower concentration. This is shown below: Put simply, osmosis is the passage of water across a partially permeable membrane from a dilute to a concentrated solution. When a substance, such as sugar, dissolves in water, the sugar molecules attract water molecules and combine with them. The water molecules now combined with sugar molecules are no longer free to
Investigating Osmosis Using Potato Cylinders
Investigating Osmosis Using Potato Cylinders Aim:- The aim of this investigation is to see how the sugar concentration of a solution eventually affects the size of a submerged potato cylinder. I am conducting this experiment to further my understanding of osmosis. The increase or decrease of the size of the potato cylinder can be explained by osmosis. ________________________________________________________________________ Introduction:- The core scientific principle, related to my investigation is that of Osmosis, below I intend to relay information thus. Osmosis:- Osmosis is basically a form of diffusion, but more specifically: it is the movement of water molecules from an area of high water concentration, through a partially permeable membrane to an area of lower water concentration. Partially permeable membrane:- A partially permeable membrane is a membrane, with holes so small that only water molecules are small enough to fit through, bigger molecule, for instance, sugar and salt are not small enough to fit through. In my experiment I will be testing Osmosis with a potato in relation to the solution that it is in, one solution will be pure water, the second will be a 5% glucose concentration, and then the next a 10% glucose concentration, and then a 15% glucose concentration. My hypothesis and the experiment will predominately affected by the type of
Diet and Breast Cancer
Diet and Breast Cancer Introduction One gets cancer when nonstandard cells are produced in the person's body. If the dysfunctional cells are not destroyed, they would multiply, and even spread to the different organs of the body. Cancer is the second leading cause of death in the United States. One of the most widespread cancers is breast cancer. It is the leading form of cancer in women worldwide. Affecting 182,000 women every year in the US, the probability of getting it across all ethnic groups is the same, though the mortality rates in minority women are higher. Also, recently, local statistics show that there has been a large surge in breast cancer cases in Singapore, doubling from 27 in 100,000 to 55, making breast cancer the second most prevalent cancer in the country after colorectal cancer in both genders, the most prevalent cancer among women. List of physical symptoms There are many breast cancer symptoms, including lumps near the breast or the underarm area, skin changes, rashes, breast pain, cysts, nipple discharge, inverted nipples, swelling, nipple tenderness, changes in size or shape of the breast, and pitting or ridges on the nipple or breast. However, most breast cancer cases do not show any obvious symptoms, or in the early stages the victim does not feel any pain. The symptoms of breast cancer might also be due to other health aliments and not
A solution effect the rate of osmosis in potato chips.
dVicky Brady 7th July 2oo3 Does the Concentration of A solution effect the rate of osmosis in potato chips The Variables The variables in this experiment are; - * Concentration * Temperature * Amount of solution * Amount of Potato * Type of Potato The variable I am going to investigate is concentration Background Knowledge The topics that I have studied on osmosis are: - * Osmosis * Osmosis in plants * Turgidity * Plasmolysis Fair Test To make this experiment a fair test I must: - * Have the same amount of solution throughout the experiment * Keep the temperature of the solution the same * Amount of Potato the same * Type of potato the same I must keep all these factors the same throughout my experiment to make it a fair test. I will make my measurements as accurate as possible and will repeat each solution 3 times. Preliminary Experiment To decide the measurements and the strength of concentration in my experiment I had to do a preliminary experiment. In my preliminary experiment I set up 6 test tubes each containing a different concentration of sugar solution. I set this up so in my final experiment I could se that all these concentrations made an effect and would give me a clear difference in results. I also decided on an amount of solution for my experiment. I decided on 30ml. This covered the chip well and didn't waste the solution. I
To investigate how long it takes catalase (an enzyme) to react with the hydrogen peroxide and if the molarity of the substrate affects the rate of reaction of the enzyme.
Catalase Investigation. Aim: To investigate how long it takes catalase (an enzyme) to react with the hydrogen peroxide and if the molarity of the substrate affects the rate of reaction of the enzyme. Introduction: Enzymes are used to speed up the rate of a chemical reaction, known as a catabolic or 'breaking down' reaction, and are made of protein. Each enzyme is specific to the material or substrate it is used with due to the shape of its active site. During the reaction, the substrate molecule fits into the enzyme molecule's active site like a 'lock and key'. The enzyme molecule then breaks the substrate molecule down and is then left free to be re-used with another molecule. In the experiment I am doing, I am using potato juice as the enzyme and hydrogen peroxide as the substrate. Catalase is a very efficient enzyme found in all living cells. All cells build up a chemical called hydrogen peroxide as a waste product. The hydrogen peroxide is toxic and dangerous and so catalase is produced to break it down into the harmless products, water and oxygen. This is done by two types of reactions called oxidation (losing electrons) and reduction (gaining electrons). When the substrate concentration is changed, it can alter the rate of the reaction. When more substrate molecules are added, more active sites can be occupied meaning that more molecules can be broken and more
Planning and Experimental Procedures.
PLANNING AND EXPERIMENTAL PROCEDURES This experiment is aimed at finding out how different strengths of sucrose solution affect the percentage change in mass of potato cells, due to osmosis. Scientific Knowledge: Osmosis is a special kind of diffusion involving water molecules and is defined as 'the movement of water molecules from an area of high water concentration to an area of low water concentration, across a semi-permeable membrane.' Osmosis can be seen in living cells: The cell membrane in cells is partially permeable and the vacuole contains a sugar/salt solution. Plant cells always have a strong cell wall surrounding them so that when they take up water by osmosis and start to swell, the cell wall prevents them from bursting. The pressure inside the cell rises and eventually the internal pressure is so high that no more water can enter the cell. Osmosis makes plant cells swell up if they are surrounded by weak solution and they become turgid. This is very useful for giving support to green plant tissue and for opening stomatal guard cells. Due to this, I have chosen to use solutions of a lower concentration ranging from a 0.2m solution to a 1.0m solution. This should provide a variety of results. The membrane of a potato has tiny holes in it which are so small that only water molecules can pass through them, and bigger molecules such as glucose become 'stuck'
To investigate the effect of varying concentration of a certain sugar solutions on the amount of osmotic activity between the solution and a potato chip of a given size.
What happens when plant tissue is bathed in water and sucrose solution? I am going to investigate the change in size and weight of a potato when bathed in the water, dilute sugar solution and concentrated sucrose. This investigation will take place under the Osmosis theory. Osmosis will cause the water molecules to travel in and out of the plant cell. Aim: To investigate the effect of varying concentration of a certain sugar solutions on the amount of osmotic activity between the solution and a potato chip of a given size. Method * First we are going to collect 6 boiling tubes each containing a concentration of sugar solution between 0.0, 0.2, 0.4, 0.6, 0.8 and 1.0 Mol DM -3. * We will then get a Cork borer of size 3; we will then insert it through the potato so we could achieve our cylindrical shape. * We will then measure out the potato samples to 3cm using the Vernier callipers. We will cut the potato samples for fine adjustment. * We will then weigh the potato samples using the electronic weighing scales. * We will then place the 18 potato samples in the test tubes each containing the different type of solutions. We will have two test tubes for each amount of mol. Each test tube will contain 3 potato samples. * We will then leave the potato samples in the solutions for about half an hour. We will use one test tube for each Mol DM -3 which increases by 0.2
Investigating the Water Potential of the potato cells.
Shama Lalji BIOLOGY COURSEWORK Investigating the Water Potential of the potato cells. INTRODUCTION: In my experiment I will be looking at the water potential of potatoes. The potato tuber is made up of plant cells, each of which is surrounded by a cell wall that is permeable and a cell membrane that is selectively permeable. This is important as water can move in and out of this permeable membrane. The tendency of water molecules to move from one place to another is called water potential. The symbol for water potential is the Greek letter psi ?. This process is called osmosis; it can be defined as the movement of water molecules from a region of higher water potential to a region of lower water potential through a partially permeable membrane. Pure water has a water potential of zero, the addition of a solute lowers the water potential so all water potential values are less then zero therefore minus. Water tends to move from a less concentrated to a more concentrated solution, i.e. from areas of low negative potential to areas of high negative potential. Equilibrium is when there is the same amount of water molecules in both solutions, which therefore stops the net movement of water molecules. Since solutes make water potential lower, the more solute the more negative the water potential becomes. The amount that the solute molecules lower the water potential of a