• Join over 1.2 million students every month
• Accelerate your learning by 29%
• Unlimited access from just £6.99 per month
Page
1. 1
1
2. 2
2
3. 3
3
4. 4
4

# The effect of varying light intensity on the rate of Photosynthesis of the aquatic plant Elodea.

Extracts from this document...

Introduction

The effect of varying light intensity on the rate of Photosynthesis of the aquatic plant Elodea Mubasher 10B Data Analysis Distance of lamp Length of bubble after 5 minutes (mm) Average length Light Intensity from plant (cm) of bubble (Lux) 5 29 49 52 56 56 59 50.17 4000 10 12 21 22 27 26 30 23 1000 15 9 9 10 12 14 13 11.17 444.4 30 2 3 3 2 5 4 3.17 111.1 50 1 2 2 1 1 2 1.50 40 Light intensity workings: 1/distance2 * 100,000 = 1/52 * 100,000 = 1/25 * 100,000 = 4000 For all the rest, workings are the same. Graph See other sheet Conclusion The pattern shown on the above graph shows that as you increase the light intensity the rate of photosynthesis increases at a decreasing rate. Sunlight + Chlorophyll Carbon dioxide + Water Oxygen + Glucose + Energy These results tell me that an increase in light intensity does increase the rate of photosynthesis. The gradual decrease in the rate of photosynthesis (the straightening of the curve) can be linked to the other factors limiting the rate of photosynthesis. ...read more.

Middle

This is because the light is increasing constantly. However the rate of photosynthesis decreases at the end because the chlorophyll has got enough energy but needs more carbon dioxide to combine with water to increase the rate. This part of the graph shows me that the increase in rate is proportional to the increase in light intensity (i.e. a straight line) and I can show this by taking some readings from the graph (See other Sheet) Evaluation I have identified two anomalous results which are highlighted on the table in red. There were errors in the experiment which could have caused this. Some human errors and some errors we can't help. Measuring the distance from the filament to the plant each time, measuring the length of the bubble and timing are human errors Also when the lamp is close to the plant it gives it heat energy as well. This will increase the rate of photosynthesis so our bubble will become bigger. This only really affects the plant when is close to it. ...read more.

Conclusion

Give it two minutes to settle and adjust to the new light intensity. 5) Start the stopwatch and count the number of bubbles produced in one minute. 6) Repeat 5 times 7) Repeat steps 4, 5 and 6 with distances 30cm, 15cm, 10cm and 5cm. Distance of lamp Amount of bubbles after 1 minute Average amount Light Intensity from plant (cm) of bubbles (Lux) 5 10 15 30 50 A glass wall is kept in front of the beaker so no heat from the lamp can affect the rate of Photosynthesis. After getting all the data I would plot some of the data on a graph. I would plot the amount of bubbles with the light intensity. Then I could find out how light intensity affects Elodea with greater accuracy. To get extra information about the rate of photosynthesis, I could try to relate some of the other limiting factors to the same experiment, as well as investigating them on their own. It could also be worthwhile to explore the effects of coloured lights on the rate of photosynthesis, which could lead to other experiments such as whether or not other types of light, such as fluorescent lights or halogen lights, would have a different effect on the rate of photosynthesis. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our GCSE Green Plants as Organisms section.

## Found what you're looking for?

• Start learning 29% faster today
• 150,000+ documents available
• Just £6.99 a month

Not the one? Search for your essay title...
• Join over 1.2 million students every month
• Accelerate your learning by 29%
• Unlimited access from just £6.99 per month

# Related GCSE Green Plants as Organisms essays

1. ## An investigation into the effect of light intensity on the rate of photosynthesis of ...

5 star(s)

It is only a few bubbles away from the line of best fit so it can't be count as an anomalous value. Suitability Independent variable: light intensity. I do not think that the chosen numbers of values are sufficient. I only chose five values because of the time limit.

2. ## Investigation to find out how light intensity effects the rate of photosynthesis

4 star(s)

While the number of oxygen bubbles was being recorded, the rate at which the plant was photosynthesizing had increased several times. A large factor in determining data accuracy is the amount of human error during experiments. The rate at which oxygen bubbles were being produced by my plant was so

1. ## Investigate the effect of light intensity and the colour of light on the rate ...

papers produced the highest rate of photosynthesis, where as the green and yellow produced the least bubbles. Enough measurements were taken to be sure of a fair test as the experiment was repeated several times so each plastic coloured sheet used had the same time and variables as the others so precise results were obtained for every test.

2. ## How temperature affects the rate of photosynthesis.

As the temperature increases, the enzymes gain more kinetic energy and vibrate more rapidly. This increases the number of successful collisions as the likelihood of the molecules binding to the active site and reacting is increased. So, as more kinetic energy is gained, more substrate molecules combine with their complementary

1. ## Investigating the effect of temperature on the rate of photosynthesis

Therefore instead of counting bubbles we will pull through all oxygen bubbles after the time is finished. Therefore all bubbles will be together and give a more accurate reading as bubbles will not be missed. The rate of photosynthesis is measured by oxygen released.

2. ## This experiment involves using a photosynthometer to investigate how temperature affects the rate of ...

It can be argued that counting the number of bubbles can be deceiving and therefore another method should be put into consideration. An alternative way of doing the same experiment more accurately can be achieved by using a photosynthometer. A freshly cut strand of the plant is suspended upside down in a boiling tube.

1. ## The aim of my investigation was to determine how limiting factors would affect the ...

Prediction I predicted that as the intensity of light is increased (moving the light closer to the elodea) the rate of photosynthesis will also increase. This is because the light that falls on the chloroplasts in the leaf is trapped by the chlorophyll.

2. ## Determine whether or not the intensity of light would affect the rate of photosynthesis ...

Here, it was in fact at a light intensity of around 950 when it seems that another factor such as temperature or carbon dioxide concentration has become a limiting factor. In my main experiment therefore, it will not be necessary to take readings above this point.

• Over 160,000 pieces
of student written work
• Annotated by
experienced teachers
• Ideas and feedback to