• 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
  6. 6
    6
  7. 7
    7
  8. 8
    8
  9. 9
    9
  10. 10
    10
  11. 11
    11
  12. 12
    12
  13. 13
    13

How does light intensity affect photosynthesis?

Extracts from this document...

Introduction

Introduction Photosynthesis is a very important process in nature. Photosynthesis is a biochemical reaction used to produce glucose using light energy, water and CO2 (Carbon Dioxide). A bye product of the reaction, photosynthesis, is Oxygen. It takes place in all green plants, which use the green chlorophyll, held in chloroplasts in the leaves, to trap light. The main site of photosynthesis is the palisade mesophyll cells in the leaf of a plant. It is these cells that contain the green chloroplasts and are very well adapted to do their task. They are near the upper side of the leaf where they can obtain the maximum amount of light, they are packed very closely together and as already mentioned contain green chloroplasts clustered towards the upper side too. Plants photosynthesise to produce food chemicals that are needed to allow them to grow. The main reaction is to produce oxygen and glucose to be changed into energy during respiration. Glucose is stored in the form of starch which is insoluble and does not affect the osmosis taking pace in the plant. As plants respire both day and night this starch is often used up during the night when photosynthesis cannot take place. The uses of glucose within the plant are for active transpiration, cell division, the production of protein and the production of cellulose. ...read more.

Middle

The optimum temperature for the enzymes to work is at roughly about 30-40 degrees, when enzymes are exposed to temperatures higher than this they are denatured and make the enzymes unable to perform at all. Variables in this experiment: The independent Variable is Light intensity. The dependant Variable is the rate of photosynthesis. To make sure this experiment is kept fair other variables are kept the same. Limiting Factors * Water. x * Light energy. x * Carbon Dioxide Concentration. x * Temperature (room temperature). V * Chlorophyll. V My experiments limiting factors will be Chlorophyll and Temperature. In my experiment water shall not be a limiting factor as the plant with be submerged in the water, this will not affect the plant in a bad way since the plant I am using is pond weed. Light energy will not be a limiting factor since it is our Independent variable. Carbon Dioxide will not be a limiting factor as I will put sodium bicarbonate into my water this will make a solution, which allows the water to make CO2 (carbon dioxide). Apparatus list * Beaker. * Flannel. * 1 metre ruler. * Elodea - also known as Canadian pond weed. * Pleistocene. * Stopwatch. * Lamp. * Sodium Bicarbonate. * Water. Method. * Set up apparatus. * Start up the lamp 100 cm away from plant in dark room. ...read more.

Conclusion

My results show me that 3 steps of results are in close arrangement and I would say that they are reliable. To make my results more reliable I could have recorded results for every 1cm as this would have been more reliable because it would have allowed me to make more accurate calculations of bubbles per minute of this experiment. Extension. I theorise that there are 3 primary light frequencies for white light (red blue green). I predicted that the chlorophyll absorbs the red and blue light and reflects the green light. Rate of Photo- synthesis R G B W No Frequency of Light Light Apparatus * Flannel. * 1 metre ruler. * Elodea - also known as Canadian pond weed. * Pleistocene. * Stopwatch. * Lamp. * Sodium Bicarbonate. * Water. * Syringe. * Beaker x2. * Different colour filters. Method. * Set up apparatus. * Start up the lamp 100 cm away from plant in dark room. * Switch lamp on. * Leave it in place for 2 minutes so it can adjust to the different light intensity. * Count number of bubbles produced by plant in one minute. * Record Results. * Move lamp forward 5cm. * Leave it for 2 minutes for plant to adjust to amount of light energy. * Count number of bubbles for 1 minute. * Repeat steps 4, 5, 6 and 7 until lamp is 5cm away from beaker. * Record 3 sets of results and repeat experiment with blue and red filters. Zaka Ahmad 11m 1 ...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

See related essaysSee related essays

Related GCSE Green Plants as Organisms essays

  1. Experiment to Investigate the Effect of Temperature on the Rate of Photosynthesis in Elodea.

    The percentage error of the syringes used for the small volumes taken was extremely small, so syringes were more practical to use in this experiment. One of the largest sources of error in this experiment was temperature control. It is extremely to keep the temperature constant for three readings using just ice and hot water.

  2. Investigating the effect of Light Intensity on Elodea.

    Light shone off the cylinder, making it hard to observe the bubbles. To overcome this problem, the method of measuring the volume of oxygen should have been carried out.

  1. How does light intensity affect the rate of photosynthesis

    until a certain level (approximately 500mm) where the line starts to curve and straighten out, which shows that the rate of photosynthesis begins to drop and is affected less by light intensity. This happens because when the a certain light intensity is reached as you increase the light intensity, it

  2. Investigating the effect of temperature on the rate of photosynthesis

    This was not very accurate; therefore all experiments should be carried out in a water bath, which will electronically keep the temperature constant. However in some water baths, even though the temperature was set, when we checked with the thermometer, it wasn't that temperature exactly.

  1. How temperature affects the rate of photosynthesis.

    Therefore, substrate molecule doesn't fit the active site and no enzyme-substrate complex is formed. This would result in the enzyme controlled reactions of photosynthesis like photolysis and carbon fixation, to take place at a lower rate or to eventually stop.

  2. The investigation is aiming to look at transpiration.

    give me a better range of result to work with and hence increase the accuracy of my next result. Also next time I will keep the experiment running for a longer time as this will increase the accuracy of my result.

  1. Find out how the amount of light, that is light intensity, affects the rate ...

    not simple instead of the method of counting the number of bubbles given off. . I can make sure that my measuring is accurate by using my preliminary work and using the inverse square law by calculating what my results should exactly be, making a prediction of my results for both the preliminary practical work done and my experiment.

  2. Absorption Spectrum of Chlorophyll.

    The plant pulp thus obtained was then shaken with the solvent in a 50 ml polypropylene tube, whose sides were wrapped with aluminum foil to minimize exposure to light. A volume of roughly 5 ml solvent per gram of plant pulp was used.

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