• 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
5. 5
5

Photosynthesis and limiting factors.

Extracts from this document...

Introduction

GCSE Biology Coursework Photosynthesis and limiting factors Plan for the experiment, which will evaluate how the rate of photosynthesis in a water plant is affected when the intensity of a light source is varied. Aim: To investigate how light intensity affects the rate of photosynthesis. Background Information: Plants need carbon dioxide, water, light and chlorophyll in order to make food; and starch and oxygen are produced, if one of these is missing then starch cannot be produced. Photosynthesis occurs rapidly or slowly, depending on the circumstances and this will determine, how much food is made in a certain period of time. Carbon dioxide and water are the raw materials of photosynthesis and they react to produce starch and oxygen, which are the products. These reactions need energy, which comes from the light and it is the chlorophyll, which enables the plant to use light energy for this process. Glucose is then formed and later turned in to starch. In order to make a prediction for my experiment I will have to research photosynthesis and it's limiting factors. A limiting factor is something that will either slow a process down or if the amount of it is increased the rate of the process will speed up. There are five limiting factors for the rate of photosynthesis, which are: light, carbon dioxide, water, temperature and chlorophyll. ...read more.

Middle

4) Carbonate the water by blowing into the beaker with a straw (this will ensure that there is a good supply of carbon dioxide for the pond weed). 5) Place a metre rule on the table to one side of the beaker. Position the beaker at a certain distance away from the lamp and it is this, distance that is the variable, which we are measuring. 6) Time a minute on the stopwatch and count how many bubbles appear during this time. 7) Repeat this three times and then take an average. 8) Move the lamp 20cm closer and repeat the experiment. 9) Record your results Throughout the experiment I will be changing the distance of the lamp from the pond weed which will allow me to assess how the light intensity affects the rate of photosynthesis. I will have to ensure that this experiment proves to be a fair test, so we can produce the most accurate results. In order to do this I will have to keep certain things such as: the size of the pond weed, the distances of the lamp from the beaker and the time spent recording and the amount of carbon dioxide which is blown through the straw into the water constant I have decided to start my experiment with the lamp being placed 100cm away from the beaker with the pond weed. ...read more.

Conclusion

There are other experiments, which we can do to investigate further the rate of photosynthesis. These include the levels of carbon dioxide, the amount of water and the temperature as each of these can effect the rate and will prevent photosynthesis happening if it is removed. I could also vary the angle of the head of the lamp when shining upon the water plant or the size of the lamp. However there are some improvements that I could make if I was to repeat this experiment again, which would allow me to support my conclusions further. If I was, to do this for a second time I would extend the range of numbers that I used and try to establish the point at which photosynthesis stops. I could also place another beaker full of water between the lamp and water plant, which would prevent the pond weed heating up and would act as a heat shield. In order to make this investigation even more accurate you could also have two people recording the time and counting the number of bubbles so that no mistakes will occur. In conclusion I feel that this experiment has successfully proved my initial thoughts and predictions and has enabled me to gain a wider understanding of the properties of photosynthesis and the affect that the light intensity has upon the rate of photosynthesis. This investigation has also given me ideas for other experiments, which could prove alternative aspects 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. How temperature affects the rate of photosynthesis.

2. Cover all the sources of light in the experiment room by covering windows with black paper or switching of any source of artificial light. (This will ensure that the lamp being used is the only light source and would eliminate the risk of light intensity being the limiting factor.) 3.

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

by external factors like light and the CO2 content of the atmosphere. In many species, it is distinguished between sun and shade leaves. Sun leaves have been exposed to large quantities of light during ontogenesis. This results in a multilayered palisade parenchyma.

1. Science Coursework

you can clearly that in the "Average No of Bubbles against Rate" graph that as the number of bubbles increases this means that the rate of photosynthesis also increases. And that in the "Average No of Bubbles against Distance" you can clearly see that as the distance increases the

2. An Investigation into Species Diversity with distance along a Pingo.

species observation5 3 7 9 13 17 17 18 20 21 20 Average 3.8 6.2 8.6 12 15 17 20 20 21 21 Conclusion: A graph of the results was plotted and the optimum size of the quadrat found to be 35cm2, because after this point there was minimal change in the different number of species.

1. Absorption Spectrum of Chlorophyll.

The last three extractions came from the same batch of spinach, while the first extraction was from a different batch of spinach. All four extracts were prepared using roughly a 1 g : 5 mL ratio of spinach leaf mass to acetone volume and were diluted 20-fold for measurement taking.

2. Investigate the factors, which affect photosynthesis.

If the photosynthesis story is sound, then the lack of any one of these three conditions should stop photosynthesis, and so stop the production of starch. In designing the experiments, it is very important to make sure that only one independent variable is altered.

1. To investigate certain factors which affect the rate of photosynthesis in plants and how ...

Carbon dioxide diffuses into the leaf from the atmosphere. Chlorophyll is the green substance found in the chloroplasts in the cells of a plant, which also gives the leaves their green colour. The chlorophyll absorbs the energy from the light source and uses the energy to combine the carbon dioxide

2. Investigation to ascertain the extent to which light intensity is a limiting factor to ...

Bubbles are produced from these when the plant is photosynthesising rapidly. Hence when the stem is cut bubbles will come from that point. The cavities provide buoyancy to keep the plant upright in the water so that the leaves can obtain maximum light for photosynthesis.

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