investigate the effect of carbon dioxide concentration on the rate of photosynthesis.
7/07/2004 Bilawal Ajmal Khan 10A H/W/K Science Investigation Aim: to investigate the effect of carbon dioxide concentration on the rate of photosynthesis. Scientific knowledge: The Elodea (Canadian pondweed) makes bubbles of oxygen when it photosynthesises. The faster it photosynthesises the faster it makes oxygen. The plant uses dissolved carbon dioxide. This can be made by adding hydrogen carbonate solution to the water. The factors which can effect how quickly a plant can make food by photosynthesis include the following. * Carbon dioxide concentration - this can be simulated by changing the volume of hydrogen carbonate solution added to the water. At low concentrations of carbon dioxide the rate of photosynthesis is very slow. As you increase the concentration of carbon dioxide the plant can make food faster and faster. There is a limit however. There comes a time when adding more carbon dioxide does not increase the rate of photosynthesis. The plant is making food as fast as it can under the conditions. * Light intensity - this can be altered by either changing the brightness of the bulb or by moving the bulb further and further away from the plant. Plants need light energy in order to make food. The more light they have the faster they can make food.
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)
Biology CourseworkTo determine if the distribution of flora across Ellerbeck is due to chance. The valley containing Eller beck possesses a huge variety of different species of plant life, particular species are often found in specific places
Biology Coursework To determine if the distribution of flora across Ellerbeck is due to chance. The valley containing Eller beck possesses a huge variety of different species of plant life, particular species are often found in specific places across the valley, to find out why these particular plants grow in the particular places I mean to investigate where different species of plants are located and what the conditions in those particular places are, investigating the effects of several factors on the distribution of these different species across a specific area of the valley. I believe that the varied distribution of the different species investigated is directly related to, and can be explained by the differences in the factors I will be measuring, that certain plants will grow in certain places in the area because they are more suitably adapted, in whatever way to the conditions in that specific place. This is a rough diagram of Ellerbeck. I plan to perform my investigation using two information gathering techniques, after first establishing a straight line across the valley by taking a bearing using a compass from one point at the top of the South side of the valley and following that bearing down the valley, across the beck and up the other side whilst performing both a line transect and an interrupted belt transect. I also plan to perform an interrupted belt
Agricultural Issues: Genetic Modification.
Agricultural Issues: Genetic Modification Scientists are developing ways to make new genetically modified (GM) food that could transform the way we feed ourselves. GM crops may enable more food to be produced from less land using less water and fewer chemicals. However, some people question whether this "gene revolution" will really reduce hunger in the world. Others worry that it is being pushed too quickly without enough consideration of its long term impact. Throughout the world there are drastic inequalities in food supply with the emergence of areas of surplus and famine. The cause of such inequalities vary from physical to human and political. Most of the responses to these problems have been driven by high income, high technology MEDC's or trans-national companies. The impacts of the Green Revolution, intensification of farming and the development of genetically-modified foods have varied. Some are economic while others have been social or environmental: some have brought benefits, while others have created problems and some may be focused upon the environment e.g., organic farming. Throughout the world genetic modification has been used freely for more that a decade as a research tool for medical purposes and in food ingredients. It holds exiting promise, not only for conquering disease, eliminating pests and contributing to the knowledge economy but for enhancing
effects of substrate concentration on the activity of the enzyme catalase.
Investigate the effects of substrate concentration on the activity of the enzyme catalase. To explain this, catalase is an enzyme found in potato cells, catalase breaks down the substrate Hydrogen-Peroxide into water + oxygen. Hydrogen Peroxide itself is a waste product found in potatoes and other fruit + vegetables. When I do this I will see with different concentrations of the substrate and see how quick the enzyme catalase works on it. The four things that affect the rate at which the substrate and enzyme would react are as follow:- * Susceptibility of temperature change. * Susceptibility to PH changes. * Enzyme concentration. * Substrate concentration. Now I will explain each one of these in detail and how they can change the rate of reaction in many different ways. Susceptibility of temperature: - Chemical reactions can be speeded up by heating the reactants, this makes molecules speed up and have sufficient energy for more successful collisions. If the temperature is too high the enzyme would vibrate and it would denature because the active-site would change shape. Susceptibility of PH changes: - Enzymes can be denatured by changes in PH. This happens because the ionisation of the Amino acids changes, the Ionic bonds with stabilise the enzyme, that shape is broken so they are no longer stable. So you need the right PH for the ionic bonds to stay stable for the
How the structure of cells is related to their function.
How the structure of cells is related to their function. All living things are made up of cells, whether its plants, humans or even bacteria. There are two different types of cells one is the prokaryotic and the other is the eukaryotic. The name cell was used by an English man who in 1665 use the first microscope and reported seeing what he described looked like the sleeping chambers in the monasteries that were called cells, in a piece of cork.1 The first of the two types is the Prokaryotic cell, the pro meaning before the nucleus as this cell has no true nucleus.2 Prokaryotic cells are surrounded by a cell wall and a cells membrane, and in some ways this makes them similar to a plant cell which is eukaryotic, but they have no nucleus or organelles inside, but they do have flagella's and cilia on the outside. The flagellum is a long whip like tail attached to the end of the prokaryotic cell which helps with its movement. The cilia are small spiked hairs that help to transport fluid in and out of the cell and for protection against harmful substances. They are also found in abundance in the eukaryotic cells in the human trachea where they collect dirt, they either by moving it down into the stomach or push it back up into to the mouth to spit it out.3 One of the most common prokaryotic cells would be bacteria, they are the smallest cellular organism, and each human being
Biology Recycling
Recycling is a way to decrease the amount of rubbish being filling up the landfill, it also helps the environment and is a sustainable development. The aim of this investigation is to find out some aspects about domestic recycling. Of particular interest is:- * What people widely recycle * How much of different things people recycle * Why people do/don't want to recycle So I created a basic questionnaire to find out what people would want to say about recycling and what changes they would want in the environment in the future. . Do you recycle? Yes No If No Thank you for your cooperation 2. Do you think that recycling is beneficial for the environment? Yes No Not sure Why do you think recycling is beneficial or harmful for the environment? _______________________________________________________________________________________________________________________________________________________________________________________________________________ 3. What resources do you recycle? Plastic Glass Paper Metal Clothes Garden Waste 4. How often are your recycling bins collected? Twice a Week Weekly Fortnightly Once in a Month Other _________________ 5. What would you change about current recycling? No Change 6. Should we increase council tax for better recycling? Yes
Artificial Cardiac Pacemakers
Research questions : Why is the constant beating of the heart important? What causes the heart to beat abnormally? What are the implications of having an abnormal heart beat? What is an artificial pacemaker and how does it regulate an abnormal heart beat? How are artificial pacemakers implanted? What are the advantages and disadvantages of using an artificial pacemaker? What are some alternatives used instead of artificial pacemakers? The importance of the heart The heart is an essential organ possessed by every living human. It is vital as it pumps blood rich in oxygen (received from the lungs) to every living cell within the body and pumps deoxygenated blood to the lungs (from the body)1. In the opposite diagram of a human heart, the blue sections represent the transport of deoxygenated blood and the red sections represent the transport of oxygenated blood. The heart is necessary in sustaining the lives of every single human being. This is because without oxygen, cells cannot carry out the process of cellular respiration (the release of energy from glucose). This means that the body cells will have insufficient energy to carry out regular functions needed for sustaining life. Every single cell in the human body is affected by the beating of the heart, as enough oxygen has to be supplied for them to function properly. Without the constant beating of the heart,
Effects of Surface Area on Catalase Activity in Potato.
Effects of Surface Area on Catalase Activity in Potato Aim To investigate the effect of surface area on the activity of Catalase in potato. Hypothesis I predict that the potato which has been cut into more pieces will have the largest surface area. A larger surface area means that there will be more catalase molecules coming in contact with the reacting substrate, hydrogen peroxide. Enzymes react when particles come into contact with their active sites; if more of the enzyme is exposed (larger surface area) a greater number of active sites will be available to react with the hydrogen peroxide. The surface area of a 5cm tube with a diameter of 2cm equals 37.0 cms² ( 2 rh+2 r² ), but a 5 cm tube cut into five 1cm segments has a surface area of 62.83 cms². Every time another segment is cut from the 5cm tube two more areas have to taken into account, this means each time the 5cm tube is cut into a piece the surface area will increase. As a larger surface area produces a higher rate of reaction, my results should show a higher volume of gas released when using a potato with a larger surface area. Background Knowledge Enzymes are proteins which can be referred to as biological catalysts. Catalysts are molecules which increase the rate of chemical reactions and remain unchanged at the end of the reaction. Enzymes are made up of a chain of amino acids which are
The Effect of pH on Catalase
The Effect of pH on Catalase Hypothesis: The rate at which catalase catalyses the decomposition of hydrogen peroxide increases to an optimum pH and then decreases as the optimum pH is exceeded. Biological knowledge: Hydrogen peroxide is produced in plant and animal cells as a by-product, which is toxic, resulting in the need of catalase to speed up the decomposition of hydrogen peroxide to water and oxygen. All microbodies contain catalase and it is the fastest known enzyme with a turnover number of 6 million. It is especially abundant in plant storage organs and in liver. It is effective over the pH range of 4.0 to 9.0 with the optimum pH of 7.6. 2H2O2(aq) catalase 2H2O(l) + O2(g) As an enzyme, its rate is affected by various factors, including pH. Changes in pH alter the ionic charge of acidic and basic groups of the enzyme. This therefore distorts the shape of the enzyme, including its active site, where substrates temporarily bind. The efficiency of forming enzyme-substrate complexes is consequently lowered and the rate of activity decreases. However, the enzyme can regain its most proficient shape, if it is not exposed to too extreme pHs, to return to its maximum rate of activity when placed back at the optimum pH. Plan: The volume of oxygen produced during the catalysed break down of hydrogen peroxide can be measured in a graduated gas syringe
