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.

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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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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

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The effect of sucrose solution concentration On osmosis in potato chips

The effect of sucrose solution concentration On osmosis in potato chips Plan I am going to cut six pieces of potato using a borer. They will all the same weight. I will make them all 0.7g. I will be able to make sure they are all the same weight-using scales. If a piece of potato is too big I will use a scalpel and a tile to trim it so they are all the same weight and then place these into a test tube each. I will hold the test tubes in a test tube rack. Using the measuring cylinder I will measure 10ml of each strength of sugar solution rinsing the measuring cylinder after each measure. This will then be added into separate test tubes with the pieces of potato. E.g. a piece of potato will have 0.0M strength; a piece of potato will have 0.2M strength and a piece of potato will have 0.4M strength etc. I will put a sticky label on each test tube stating what strength of sugar solution it contains. I will then leave these for 2 hours and see what happens then record my results. APPARATUS A potato Sugar solutions (0.0, 0.2, 0.4, 0.6, 0.8, and 1.0) Borer Scalpel Tweezers Scales 6 test tubes Test tube rack Measuring cylinder I will measure the amount of sugar solution in the test tubes. I will change the strength of sugar solution in each test tube. To make the experiment a fair test I will keep the weight of the pieces the same weight I will also only add the same

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Effect of enzyme concentration on initial rate of reaction

Effect of enzyme concentration on initial rate of reaction The objective of this experiment is to determine how differentiating the concentration of the enzyme catalase affects the initial rate of reaction, in the decomposition of Hydrogen Peroxide (H2O2) The equation of this reaction is: Hydrogen Peroxide(aq) --> Water(l) + Oxygen(g) 2H2O2(aq) + catalase(aq) --> 2H2O(l) + O2(g) The source of the enzyme Catalase in this experiment will be yeast, specifically the Saccharomyces Cerewisea strain, as it is easy to obtain and very safe with no harmful effects to the environment. The technique used to obtain a set of results will be the downward displacement method, where evolved oxygen product from the reaction is passed through a delivery tube and into a water filled burette, pushing the water out of the burette, leaving obtainable results of Oxygen collected. These results will be taken every 5 seconds for two minutes and will give the rate of reaction. My Equipment will be: * Burette * Side-arm Conical Flask * Bung * Tubing * Yeast * Hydrogen peroxide * Water Bath * Water/Margarine Tub * Distilled water/pH7 buffer * Stopwatch I chose to have a burette to collect the evolved Oxygen, as it has a great degree of accuracy. The gas can be measured to 0.05ml or 0.5cm3. I chose to have a side arm conical flask to provide a source for the evolved oxygen to travel

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Importance of Water.

Importance of Water Our Earth seems to be unique among the other known celestial bodies. It has water, which covers three-fourths of its surface and constitutes 60-70 wt % of the living world. Water regenerates and is redistributed through evaporation, making it seem endlessly renewable. So why worry? Actually, only 1% of the world's water is usable to us. About 97% is salty sea water, and 2% is frozen in glaciers and polar ice caps. Thus that 1% of the world's water supply is a precious commodity necessary for our survival. Dehydration (lack of water) will kill us faster than starvation (lack of food). Since the plants and animals we eat also depend on water, lack of it could cause both dehydration and starvation. The scenario gets worse. Water that looks drinkable can contain harmful elements, which could cause illness and death if ingested. Good water is essential to body cleansing. It's obvious. It sounds like a truism. Your body goes down fast without water. Making up almost three-fourths of the body, every cell is regulated, monitored and dependent on an efficient flow of water. Not one of the processes in our bodies could take place without water. Water is something that we take for granted. But how many of us really understand how essential water is or what happens to our body if it doesn't receive pure water every day, free of chemicals and

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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

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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

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An investigation into the effect of a germination inhibitor on the germination of seeds.

GERMINATION INHIBITORS An investigation into the effect of a germination inhibitor on the germination of seeds. INTRODUCTION The necessary conditions For a seed to germinate there are specific conditions different seeds need. In this experiment, cress seeds are to be used. Going through the basics first though, for a seed to successfully germinate there needs to be: o An adequate supply of water o A suitable temperature o An appropriate partial pressure of oxygen o A suitable supply of light Water uptake is a crucial part of the necessary conditions because germination can only commence after the uptake of water by the seed. Water absorption is imbibition. The optimum temperature for germination is the optimum for the enzymes involved in mobilisation of food reserves, provided that other factors are not limiting. This temperature varies from species to species (i.e. 1 - 45°C). Respiration makes available the energy for metabolism and growth. Germinating seeds respire very rapidly, and require oxygen for aerobic respiration. Seeds will not germinate in the total absence of oxygen. Diffusion of oxygen through the testa may be slow, however, and in the early stages of germination seeds may rely on some anaerobic respiration, at least until the testa has ruptured. So this explains why water, oxygen and a suitable temperature are needed for germination, therefore

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Science Investigation Into What Affects The Rate That An Aspirin Dissolves At In Water

Science Investigation Into What Affects The Rate That An Aspirin Dissolves At In Water By Owain Bristow 10E3 I am investigating how two different factors will separately affect the rate at which a single aspirin dissolves in water, these are: * Temperature of water. * Surface area of aspirin. I could investigate the effects of stirring/agitating the solution and the use of a possible catalyst. However I feel it would be to hard to do the former accurately and fairly and regarding the latter there is no known catalyst that will speed up the dissolution of an aspirin in water, according to many science sites on the Internet. Concentration of water and aspirin would not affect the dissolution rate as at any time only the water touching the aspirin's outside can cause it to dissolve, this amount is always the same regardless of the amount of water, (providing the surface area remains constant). Temperature Method: ) I will place 50ml of water in a beaker with a thermometer. 2) I will heat the water until it reaches the required temperature. 3) I will remove the beaker from the heat, take out the thermometer and put one aspirin into the water. 4) I will time how long it takes for the cross, drawn underneath the beaker, to disappear, and then record it on a table. I will move up in ten-degree steps between each successive experiment from a range of 30-90ºC. These

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