Photosynthesis Lab
Photosynthesis Lab Jillian Wilson Framingham State College March 29th, 2002 Introduction Photosynthesis is a very important process. It uses sunlight, Carbon dioxide, and water to make food, and gain energy. The process occurs in three stages: the capturing on energy from sunlight, the formation of ATP (from that energy), and the synthesis of CO2 (by use of ATP). The equation for photosynthesis can be written as: 6CO2 + 12 H2O + light energy --> C6h1206 + 6O2 + 6H2O But why is it important? By releasing oxygen and consuming carbon dioxide, photosynthesis has transformed the world into the hospitable environment we know today. Both directly and indirectly, photosynthesis fills all of our food requirements and many of our needs for fiber and building materials. The energy stored in petroleum, natural gas and coal all came from the sun via photosynthesis, as does the energy in firewood, which is a major fuel in many parts of the world. This being the case, scientific research into photosynthesis is vitally important. In this lab, we studied the effects of light intensity on photosynthetic rate, and the relationship between color (essentially light wavelength) and photosynthetic rate. This was an interesting process as it involved the measuring of bubbles released from a plant under water, thus determining the rate of photosynthesis by the amount of oxygen released. The
Animal Testing
Is Animal Testing/Research Necessary for Advancing in Medicine? Introduction: Animal testing involves using non-human animals for scientific procedures. Animal research can be used for a number of things such as developing new drugs to improve health, learning about animals and the human body, aiding scientific advances and ensuring other products do not harm humans. Vaccinations against diseases like polio, rabies, measles, mumps and rubella were developed because they were tested on animals. Also the development of open-heart surgery and organ transplants depended on operations done on animals. In 2006 approximately two million animals were used in procedures. Animals that are normally used in tests and experiments include: rats, mice, rabbits, monkeys, guinea-pigs, cats, dogs, fish, birds, pigs, horse, sheep and hamsters. This pie chart shows the types of animals used in procedures. A large proportion of experiments are conducted on mice. (1) Those who are extremely against animal testing (animal rights activists) would refer to it as 'vivisection'. This means the 'cutting up of animals'. They refer to animal testing being morally wrong and cruel. However this is just one view, others are not so against animal testing. Others may believe that animal testing is necessary for some purposes for example medicinal purposes yet not for beauty products. Methods of
Aseptic Technique.
Aseptic Technique * Wipe the bench you are working on with disinfectant - this kills all the bacteria that may already be on the bench at the start of the experiment. The bench also needs to be wiped down at the end of the experiment. * Wipe tray that you will put all the equipment on with disinfectant - this is done to kill all the bacteria that may already be on the tray so that the sterilised equipment is not contaminated. * Sterilise all equipment - the equipment used is put in an autoclave which sterilises it so that bacteria on the equipment are killed and the equipment is ready to be used. * Light Bunsen Burner near equipment - this is done to create an up draught of air away from the bench to prevent contamination of cultures. * Wash your hands with antibacterial soap - this will get rid of any bacteria that may already be o your hands. Other safety precautions: * Wear safety goggles to protect your eyes * Wear a lab coat to protect your clothes from being contaminated with the cultures. * Cover all cuts Procedure . Collect all sterilised equipment and put on the tray that has already been disinfected. 2. Collect 10cm3 of the water sample in a sterile test tube and cover. 3. Prepare 4 serial dilutions of the original (10 , 10 , 10 , 10 ). Make sure a different pipette is used for each sample or else the samples will be contaminated. 4. Label the
Nuclear Power
Nuclear Power Nuclear power plants create electricity using the energy released by splitting atoms to boil water and create steam which turns a steam turbine driving a generator. Since no fuel is burned, there are no gases or pollutants released into the air. The water used to create steam is isolated from radiation and any hot water to be discharged is cooled down in ponds or in tall cooling towers. Nuclear waste is the only byproduct of nuclear power and is packaged and stored rather than released into the environment. Unlike other fossil fuels, nuclear power plants release almost no emissions into the environment. Two different light-water reactor designs are currently in use, the Pressurised Water Reactor (PWR) and the Boiling Water Reactor (BWR). Diagram of a PWR In a PWR, the heat is removed from the reactor by water flowing in a closed pressurized loop. The heat is transferred to a second water loop through a heat exchanger. The second loop is kept at a lower pressure, allowing the water to boil and create steam, which is used to turn the turbine-generator and produce electricity. Afterward, the steam is condensed into water and returned to the heat exchanger. Diagram of a BWR In a BWR, water boils inside the reactor itself, and the steam goes directly to the turbine-generator to produce electricity. Here, too, the steam is condensed and reused. How a
Investigate the effect of changing light intensity on the rate of photosynthesis.
Aim My aim is to investigate the effect of changing light intensity on the rate of photosynthesis. Introduction This is an investigation into how the amount of light provided to a plant can affect the rate of photosynthesis in a plant when it has a constant supply of reactants. The reactants in this experiment are H2O(water), CO2(carbon dioxide) and light. The products are glucose and oxygen. The glucose is stored in the plant as starch and also used for respiration and growth of the plant. The oxygen is given off into the surroundings, this is what we will be measuring. The word equation for this process is: sunlight 6CO2 + 6H2O-----C6H12O6 + 6O2 There are several factors that affect the rate of photosynthesis- Temperature- the warmer the surroundings the higher the rate of photosynthesis. This is because this is an enzyme based process. This will happen only if the plant is given an adequate supply of water and carbon dioxide. But if the temperature becomes to high the structure of the cells unravels and they become denatured. Carbon Dioxide Concentration-The higher the concentration of carbon dioxide the higher the rate of photosynthesis. There is an upper limit but too much carbon dioxide will have no damaging effects on the plant itself. Water- The amount of water must not be too high because this can cause the plant to become waterlogged. This stops
Investigate the effect of solution concentration on osmosis
Investigate the effect of solution concentration on osmosis. Aim The aim of my experiment is to find out the effect of sucrose solution concentration on osmosis in potato cylinders. To do this I will conduct an experiment. Introduction To carry out my experiment, I will place the potato tubes into a solution containing part sucrose and part water. The potato tubes will all be cut out of the potato using a cork borer and will all be cut to the length of 25mm. This will remain constant throughout each experiment. Each of the 5 times I do the experiment, I will increase the concentration of the solution by 0.25 mols/dm³, starting from just water in, going up to 0.25 mols/dm³, 0.50 mols/dm³, 0.75 mols/dm³ and finally 1.00 mol/dm³. The solution shall be my variable. The other variables I could have used are: - The temperature of the solution. - The size of the potato cylinders. - The amount of solution. - The time left in the solution. I will test each solution 3 times to reduce any anomalous results. After I have kept the potato tube in the solution for 60 minutes, I will take it out and re-measure it, I will then calculate the average of all three experiments and then calculate the difference between the final average length and the original length. This will allow me to plot a graph and determine the effect of the different concentration of sucrose solution on
Investigate the effect of temperature on the activity of catalase (from potato)
Arefin Khan The Effect of Temperature on Catalase Enzyme Aim: Investigate the effect of temperature on the activity of catalase (from potato). Introduction: Enzymes are biological catalysts. They speed up metabolic reactions in the body but remain chemically unchanged themselves. Enzymes contain an active site. This is a region, normally a depression or cleft, to which another molecule may bind. This molecule is known as the substrate, and is usually specific to the active site of the particular enzyme, which breaks it down. Substrates will not usually fit into any other active sites other than that of the enzyme it is specified to. This can be explained as a lock and key model, where the lock and key are specific to each other, only, that there are many of the same kinds of lock and key when it come to the enzymes. Just as lock and keys have three-dimensional shapes, proteins are also three-dimensional. Usually, there is only one active site on an enzyme; however there can be more. Some energy releasing reactions in cells produce hydrogen peroxide. This is acidic, and can thus, kill cells. Normally, hydrogen peroxide decomposes to form hydrogen and oxygen: 2H2O2 2H2O + O2 However, this process is very lengthy. There is an enzyme known as catalase in cells which dramatically increases the rate of decomposition of hydrogen peroxide. catalase 2H2O2 2H2O + O2 This
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.
Skill Area P: Planning 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. Hypothesis: Osmosis is defined as the net movement of water or any other solution's 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. 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. The graph above shows a simple curve obtained when the concentration of the solution is plotted against the percentage change in mass.
Investigate the effect on potato chips in different concentration of sugar solutions
Aim: - To investigate the effect on potato chips in different concentration of sugar solutions. Introduction: - Osmosis is the net movement of water molecules from a region where there is a higher concentration of water molecules to the region where there is lower concentration of water molecules. The water molecues move through a partially permeable membrane, which allows the smaller molecules to pass but not the big ones. The diffusion of molecules from the region of higher concentration to the region of lower concentration until the concentration of water molecules has become same in both the areas. Precautions to make the test fair: For a fair test certain factors had to be kept in mind. I decided to choose sugar solutions of different concentrations so that I get different sets of result containing information about the change in mass, change in length and the mass and length of potato chips after the experiment. If any of the factors were not kept constant it would mean that the test is not fair. Such as: - * All the potato chips have to be of the same length so that the area at which osmosis occurs is the same. * Doing all the tests at one temperature will control the temperature. For the purpose of my experiment I am going to do all the experiments at room temperature. * I will use the same potato so that the potential to absorb water is same. * The mass
Investigate the movement of water into and out of plant cells by osmosis.
Potato Cores in Salt Solution Scenario Plants in the soil have their roots in a dilute solution of mineral ions. When they are suddenly flooded with seawater, concentration of which is 0.3 molar Sodium Chloride, they are observed to wilt and become flaccid. Aim The aim of this experiment is to investigate the movement of water into and out of plant cells by osmosis. The cells chosen for study will be taken from potato tubers as they provide a ready supply of uniform material. Background Information Any substance dissolved in water is called a solute; a solvent is a liquid that is able to dissolve another substance, called a solute, to form a solution. The water content of plants varies depending on environmental conditions. In land plants it plays a vital role in structural support and mineral transport and thus a lack of water may lead to wilting or possibly death. Water is mainly absorbed through the roots, which are covered in specially adapted root hair cells, with large surface areas and thin cell walls to aid absorption by osmosis. The evaporation of water through stomata on plant leaves causes a transpiration stream, causing the water to be drawn up through xylem vessels. Osmosis is the flow of water molecules by diffusion through a partially permeable membrane from areas of high water potential (low solute concentrations) to regions of
