Rate of Photosynthesis Experiments

 

The rate of photosynthesis can be measured directly by the production of oxygen.  This is most easily achieved using an aquatic plant, such as Elodea.  The oxygen can either be collected and measured or the amount of bubbles produced can be counted.

 

Using the above information devise a simple experiment to investigate the effect of either

  1. temperature,
  2. light intensity, or
  3. carbon dioxide concentration

on the rate of photosynthesis.

 

Make at least three separate measurements and if time allows repeat any anomalous results. Record your results and write a conclusion that you will present to the rest of the class along with a summary handout of your findings.

 

Tips

Cut the aquatic plant under the water. This allows the axygen to flow out more easily.

 

Temperature – it is easy to alter the temperature of the water.  It is best to use a hot plate not a Bunsen.

 

Light intensity – there are lamps that you can use to increase and decrease light intensity

 

Carbon dioxide – if you can sodium bicarbonate to water the level of dissolved carbon dioxide increases.  Use only very small amonts, no more that 0.5g per 1000cm3.