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What Affects The Rate Of Photosynthesis?

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What Affects The Rate Of Photosynthesis? Aim: To investigate the factors that, affect the rate of photosynthesis. Planning: I will get some pondweed and place and place it in a beaker with some water and sodium hydrogen carbonate. Then I will shine a lamp on the pondweed and when it starts to release bubbles, I will start to count the bubbles. Then I will adjust the lamp to distances of 5 cm, 10 cm, 20 cm and 30 cm and try to get different results. Introduction: The experiments in this topic tells us that plants need carbon dioxide, water, light and chlorophyll in order to make food for themselves; and starch and oxygen are produced. Carbon dioxide and water are raw materials of photosynthesis. They react in some way to produce starch and oxygen, the products. We now know that this is not a simple reaction, but takes place in a series of steps. ...read more.


Prediction: 3. All plants need water for the process of photosynthesis and if there isn't enough of it the rate of photosynthesis will slow down rapidly. When the plant lacks water, the stomata closes, it also closes when the plant lacks CO2, which means that CO2 is linked with water. The plant makes its food by mixing CO2 and water in the chloroplasts. Prediction: 4. And finally I predict that increasing the light intensity will also increase the rate of photosynthesis at a continuous scale where light is inversely balanced to distance from light source to plant. This is true to a certain point until another factor is limiting. Pigments in the leaf such as chlorophyll absorb light energy. The leaf doesn't absorb green or yellow much but reflects them well. If you decrease the amount of light, the rate of photosynthesis will also decrease. Method: 1. Set up the apparatus as shown on the previous page but leaving out the pondweed, test tube and sodium hydrogen carbonate. ...read more.


Temperature was a factor controlled by the lamp being used. Even though that the pondweed was in a test tube, that did not stop some of the heat from reaching the plant. The extra heat, however did not affect the temperature of the water. Conclusion: From the results, which I have gathered, I can state that an increase in light intensity certainly does increase the rate of photosynthesis. When measuring light intensity in terms of distance, the greater the distance, the slower the rate of photosynthesis. While the rate of photosynthesis was decreasing, the rate at which it was decreasing was also decelerating. This is where the line graph decreased. The decreasing of the line graph can be explained by the fact that, light intensity is inversely proportional to the distance. This means that as distance increases, the light intensity decreases at an exceptional rate. If light intensity decreases exceptionally, photosynthetic rates that depend on light intensity also decreases exceptionally. The line graph would eventually reach to `0' where photosynthesis stops as light intensity limits this rate. ...read more.

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