Investigating the effect of light intensity on the rate of photosynthesis.
Investigating the effect of light intensity on the rate of photosynthesis. Aim: We are going to investigate the effect of changing light intensity on the rate of photosynthesis on Eloden pondweed. Factors affecting the rate of photosynthesis. . Heat-high temperatures can destroy enzymes. Very low temperatures slow enzymes down. 2. Light intensity- high light intensity increases photosynthesis. 3. Carbon dioxide-high levels increase rate of photosynthesis. Variables- things can change. What will we measure? * The number of oxygen bubbles produced in a given time. * Variables- distance from the lamp, measure the temperature of the water, volume of water, length of the plant. Range of five measurment, 5 repeats, average results. Method. The equipment I will need is: beaker, thermometer, glass rod cotton pondweed, boiling tube containing dilute hydrogen carbonate, lamp and a meter ruler. I will make it a fair test by having range of five measurements and 5 repeats. To make the experiment safe I will where safety goggles. Things I could change. What I will keep the same. * The amount of pondweed. * The amount of sodium hydrogen carbonate. * I will not change the 5 measurements. * The amount of water. I can make the results as reliable as possible by doing more than 3 repeats and a range of 5 measurements. To make sure I have enough results to make a graph, I
Investigating the enzyme Catalase
Investigating the enzyme Catalase-AS biology coursework Introduction The experiment being carried out will find the effects of the enzyme catalase with different concentrations of substrate. . This enzyme is common in living organisms and its function is to catalyze the decomposition of hydrogen peroxide to water and oxygen. Hydrogen peroxide is a poisonous by product of metabolism, it can kill cells. Catalase from a potato will be used. An enzyme is a protein produced by any living organism which acts as a catalyst in specific reactions without being used up. All cells produce H2O2 2H2O2 › 2H2O + O2 in Metabolism. It is toxic so it is broken down by catalase. The factors that affect the enzymes are: Temperature changes - catalase works well at high temperatures up to 45°C. This is because they gain kinetic energy so the move around faster, more substrates can be broken down in the same amount of time. After then however the enzymes start to denature. At a low temperature the enzymes do not have as much kinetic energy so they don't work as fast. If its higher than 45°C, then the loses its tertiary structure as the bonds holding it together are broken so the enzyme loses its active site shape. pH changes - There is a narrow range of pH's that the catalase can work in. It works well at pH 7. If the pH goes above or below this, there will be a change in the
Science in the News: Should old people be allowed to drive?
Environmental Social Economical This is my coursework broken down into digestible chunks. Anything I used came from this piece of text. For (they should be able to drive) > They are experienced in driving. Therefore have more practises driving on the road. [8] > More convenient, you can get where you want, whenever you want. [11] > Not as dangerous in a car, as elderly people may feel intimidated at a bus stop. [12] > It is discrimination to not let them drive. [13] > They have passed there test, so they have as much right to drive than anyone else. [14] > Gives money to the Government for road tax. > Petrol stations gain money. > They can talk with family and friends comfortably without feeling awkward around others. > If more old people drive they will buy new cars, from car dealers. Putting more money into the local economy, adding to the Multiplying effect. > It they drive a car, they will pay money towards having it cleaned, giving money to car cleaners. Against (They shouldn't be able to drive) > Poorer eyesight is very common with older people. [15] > Adds to Global warmer. [16] > Uses fossil fues > Slower reaction time as you get older. [2] and > Saves money as petrol is rising. [17] > It is more sociable to go on a bus and talk with the community. > Could put others in danger. >
Sensor Project
Sensor Project Liquid level based on flotation and a rotary potentiometer Plan By using a rotary potentiometer connected to a cylindrical float plastic, measure the water level in a tank filling with water, as the water level moves up, the float attached to the rotary potentiometer will moves accordingly as it floats on top of the water. Find out the relationship between the volume of water and the voltage using the potentiometer as it move accordingly with the level of water. Rotary potentiometer - Movement to cause change of voltage Float arm - Connect the polystyrene to the potentiometer Circular Polystyrene - Moves as level of water goes up Measuring Cylinder - Measure the amount of water added Digital Meter - Measure the voltage across the potentiometer Clamp - Hold the potentiometer above the tank Tank - Contain water Power pack - Supply power to the potentiometer Protractor - Measure the angle of the float arm movement The Sensor Potentiometer - A variable resistor that functions as a voltage divider. Measurements to record in the experiment: Volume of Water added each time Angle of Movement of the float arm Voltage across the Potentiometer I am going to take these three measurements to investigate the relationship of the volume of water and the voltage of potentiometer when water is added to the tank. As the tank
Potato and Osmosis Investigation
Potato and Osmosis Investigation Planning Aim: To investigate the effect of varying concentration of a certain sugar solution on the rate of osmosis between the solution and a potato chip of a given size. Hypothesis: Osmosis is defined as the 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. 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. Further information on potato plant cells: Plant cells always have a strong cell wall surrounding them. When they take up water by
Potato and osmosis Investigation.
GCSE Biology- Osmosis Coursework Potato and osmosis Investigation Planning Aim: To investigate the osmotic activity which occurs when the concentration of a certain sugar solution is varied and the effect this has on potato chips. I must conclude this investigation by verifying the connection with the water potential/concentration of solution on potato chips (if there is one). Hypothesis: Osmosis is defined as the net movement (diffusion) of water or any other molecules or solutions from an area of high concentration to an area of low. This movement must take place across a partially permeable membrane such as a cell wall, which lets in smaller molecules like water but does not allow bigger molecules to pass through. The molecules will continue to diffuse until the area in which the are found reaches a state of equilibrium, meaning that the molecules are randomly distributed throughout an object, with no area having higher or lowers concentration than any other. Osmosis makes plants cells swell up if there're surrounded by weak solution ad they become (Turgid). This is real useful for giving support to green plant tissue and for opening stomata guard cells. Animal cells don't have a cell wall and can easily burst if put into pure water because they take in so much water by osmosis. When a Plant is well watered, all its cells will draw water into themselves by osmosis
Potato Chip Experiment.
Potato Chip Experiment Preliminary Practical Work: In the preliminary work I used two potatoes and two different solutions, Sucrose and Water. I cut obtained the potato by using a cork borer and then made sure that they had the same or nearly the same mass and took down the masses. I put the two chips in test tubes and in one test tube I put water and in the other I put Sucrose. I used 4.5 centimetre cubed of both solutions. I left both of the solutions for 24 hours and then dried the chips and took down the end mass of them. I noticed that the mass of the potato chip in the sucrose solution and decreased and that the mass of the chip in the water had increased. Results table for preliminary: Solution Start Mass (g) End Mass (g) Difference in mass Percentage Change (%) Sucrose 0.5 .67 .91 0.24 4.37 Distilled Water .70 .51 -0.19 1.18 From these results I can see that the potato sucrose solution decreased in mass and the potato in water increased. I have decided from these results that I will use the same amount of sucrose and water solution in the test tubes because it covers the potato. I have decided because I will be using more pieces of potato in my real experiment I will need to use the same potato for all the pieces so I will make my potato chips small to use less potato. This means they will weigh about half as much as they did in the preliminary
The role of water in the lives of organisms
The role of water in the lives of organisms Water is perhaps the most important molecule for the survival and life of all living organisms because there is a wide spectrum of roles that it plays. The fact that the earth's surface consists of 70.8% water shows its significance and importance. Firstly, water has the chemical formula H(0 (two Hydrogen atoms to one Oxygen atom), the covalent bonds between which create cohesive forces. Water has a very high specific heat capacity, measuring 4,200 Joules, creating a stable environment for organisms to live in. This means that water does not heat up or cool down too rapidly due to the difficulty in breaking the hydrogen bonds, which restricts the movement of the water molecules. This property of water is beneficial to aquatic organisms (e.g. Fish, Jellyfish), as they do not have to keep adapting their own body temperatures for survival. Another property water has is its insulating nature in lakes and rivers. As water cools toward 0°C, the water molecules slow down to form the maximum number of hydrogen bonds. As this process continues, water molecules must give enough space for all four hydrogen bonds to fit, causing the water to expand as it freezes to form ice. Ice is less dense than the liquid form and therefore floats, a property very significant to the survival of fish as this layer of ice insulates the liquid water below
The roles water in living organisms and water as a habitat for organisms
The roles water in living organisms and water as a habitat for organisms Introduction Water is the most abundant liquid on the planet. It covers 2/3rds of the earth's surface, and at least 60% of living organisms is water. This value may be as large as 99% - in a jellyfish. The reason for such a large amount of water making up organisms is the fact that it is a major cell constituent - more on that later. Water is a simple molecule yet has many interesting properties which contribute to its importance. Structure The molecule is polar, because the electrons in the bonds between O and H are pulled slightly toward the O. this means that the O atom is slightly negative and the two H atoms are slightly positive (shown by ?+ and ?-). The electrons are shown as small dots; note they are closer to the O. These properties are described more in the solvent section. db. Water is made up of two hydrogen atoms bonded to one oxygen atom. They are covalently bonded and the intramolecular covalent bonds are very strong. The structure is non-linear, due to the electron pair repulsion of the two lone pairs of electrons on the oxygen atom. Major cell constituent Often 2/3rds or more of living cells are water. The water is found mainly in the cytoplasm, and it plays a vital role in many functions of the cell: in all organisms - metabolism, and in plants photosynthesis and support. The
This experiment aims to discover how the intensity of an exercise can affect the heart rate of any given individual by testing their pulse rate after different amounts of exercise.
INTRODUCTION: This experiment aims to discover how the intensity of an exercise can affect the heart rate of any given individual by testing their pulse rate after different amounts of exercise. THEORY: Although we have chosen to investigate the amount of exercise and to measure the heart rate by using the pulse (two fingers on the main vein in the neck and count the beats over a period of 1 minute), there are other ways in which we could go about it. We felt that these ways were best to suit our experiment. How will the main input variable, i.e. the intensity of exercise, affect the output variable, i.e. the heart rate? First we need to know a bit about the heart and blood system. The heart is, besides the brain, one of the most important organs. It is a pump no bigger than your fist that pumps blood around the body. This means it must be incredibly strong and powerful. The heart acts as a double pump, pumping two circuits. One to the body (and head) and the other to the lungs. One side of the heart pumps de-oxygenated blood (the right side), and the left side pumps the oxygenated blood. But the heart's duties are much broader than simply pumping blood continuously throughout life. The heart must also be able to respond to changes in the body's demand for oxygen. The heart works very differently during sleep, for example, than in the middle of a 5-kilometre run. This is
