Classwork Wednesday, 08 October 2003 Photosynthesis Exploration Aim – To see how changing the light intensity affects the rate of photosynthesis. Prediction – I predict that as the amount of light is reduced (lamp steadily being moved away), the rate of photosynthesis will slow down. Consequently the nearer the lamp is to the plant, the more oxygen bubbles are produced. Hypothesis – The reason I predicted that if the amount of light is reduced the rate of photosynthesis will slow down is because as the light is moved away the amount of oxygen bubbles being produced will also decrease. Photosynthesis Word Equation: C 02 + H 20 = Glucose + water / oxygen The equation shows that there are two more reliable elements needed to form glucose and oxygen (photosynthesis).
These elements are essential and without any of them this process can’t be done.
And the more of the substances will increase the process and make it quicker. Sunlight is a key factor in Photosynthesis without Sunlight Photosynthesis cannot function successfully. The more light and heat given off the plant the more energy is going in, which means the more bubbles produced. Sunlight is an Input of Photosynthesis, if the lamp is the alternative to the sun the light from the lamp will make the weed grow. The lamp produces the sunlight which gives the plant its energy which then it produces its own food and grows – Photosynthesis. PLANNING – Independent: I will be changing the distance of my lamp (light bulb) to the weed (bottom of the beaker); my distance apart will measure at 10 cm, 20, 30, 40, and 50.
... with the light from the desk lamp therefore more photosynthesis will occur which will mean more oxygen and glucose will be produced. Apparatus Funnel. ... was not much photosynthesis taken place only about 13 bubbles of oxygen were produced, but when the desk lamp was 0 cm ... They do this by a process called photosynthesis. For photosynthesis to occur they need sunlight energy. This energy is absorbed by ...
Dependant: I will be measuring the amount of oxygen bubbles being given off from the tip of the stem of the weed in the beaker of water, in a certain amount of time. This is known as “photosynthesis”, because the weed is producing energy which then is produced into food and then it grows. fair test – To enable all experiments to become a fair test, certain rules and regulations should be followed. In our experiment we will determine if it is a fair test and consequently whether it will be a success. For starters, we will make sure that the measurements are precise and exact! This means using the same equipment i. e.
ruler because some differ. I will also use the same lamp because each lamp has different light intensities depending on how much the light bulb has been worn down. I will make sure that the water in the beaker is the same each time. And throughout the whole experiment we will keep the same piece of weed, because different bits of weed produce photosynthesis at different rates. In this experiment I will be conducting a pilot test to gain accurate results; and to enable sustainable and efficient recordings – to make it a fair test. A pilot test: This is where I done the test once through and then done it again.
Through my piolet test I found that: Distance (cm) 1 st 10 seconds 2 nd 10 seconds Average Light intensity 10 cm 26 32 29 81% 20 cm 13 11 12 74% 30 cm 7 10 9 62% 40 cm 2 4 3 49% 50 cm 0 1 1 22% The benefits of using a piolet test is that you can compare your piolet results to those of the new test that you conducted, which furthermore is a good way of seeing if the test was a fair one. Apparatus – In this experiment I will be using the following equipment, I will make sure that I set it up sensibly and efficiently and I will make sure it is packed away in the way that I found it: 1. Ruler, used for measuring the distance between the light bulb and the weed in the beaker. 2. Beaker, to hold the plant in the water, and will be filled with water. 3.
Coliform bacteria are good indicator organisms for the presence of pathogenic bacteria due to their real tionship with these pathogenic bacteria, their relative ease of determination by simple methods, and by their occurrence in large quantities in human feces. The MPN method used in this experiment is one of the prescribed techniques for the determination of these coliform bacteria from the ...
Lamp, used as an artificial light to shine on the plant to enable photosynthesis to happen. 4. Stop Clock, used to time the rate of oxygen bubbles produced (rate of photosynthesis).
5. Water, supplies the nutrients. 6.
Weed (plant used, which produces photosynthesis) 7. Sodium Carbonate (acts as a catalyst, speeds up the reaction) – makes the water more pure. 8. Paper clip, which is used to hold the plant at the bottom of the beaker and so it is still and does not float around. Diagram – Step By Step Plan – 1) Firstly, I set up all equipment thoroughly – as shown in diagram, and in a sensible and efficient manner. 2) I then measured 10 cm between the light bulb and the bottom of the beaker and recorded the light intensity, and then counted for 10 seconds how many bubbles were given off, and then I waited a further 10 seconds and counted again and then I can make an average of my results.
3) Once all the results had been collected complete Conclusion, evaluation, graph and mostly draw up a results table. 4) Tidy up equipment and put away in a sensible manner. Safety – On conducting this experiment, safety is a key issue = abide by these rules: . Tuck in ties. Tuck in stools. Tie long hair back.
Have a clear working space… Do not run around… Stop when the teacher tells you too… Any spillages or breakages tell the teacher immediately…
Be careful of the water and the electricity coming from the lamp. Abide by these rules and have a safe, successful and easy experiment.