1 / 11

Limiting factors in Photosynthesis

Limiting factors in Photosynthesis. Discuss the limiting factors in photosynthesis with reference to carbon dioxide concentration, light intensity and temperature. Law of limiting factors.

kuper
Télécharger la présentation

Limiting factors in Photosynthesis

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Limiting factors in Photosynthesis • Discuss the limiting factors in photosynthesis with reference to carbon dioxide concentration, light intensity and temperature.

  2. Law of limiting factors • The limiting factor for a metabolic process is the factor that is present at the lowest or least favourable value.

  3. Rate of photosynthesis 0.1 0.5 Carbon dioxide conc Carbon dioxide concentration • Average carbon dioxide content of the atmosphere is 0.03-0.04% • Increase in CO2 up to 0.5% will increase the rate of photosynthesis • BUT optimum is 0.1%

  4. With reference to the graph: • What makes 0.1% the optimum figure? • Why is there little point in recording rates above the 0.5% CO2 concentration?

  5. Light intensity • Experiments carried out by Blackmann • At low light intensities, the rate of photosynthesis increases as light increases • Beyond 20 kilolux the rate levels off

  6. Effect of light • Allows opening of stomata so CO2 can enter • Absorbed by chlorophyll excites electrons • Splits water molecules  photolysis

  7. Light intensity and the compensation point

  8. Effect of temperature • Mostly affects enzyme controlled reactions of Calvin cycle • At high light intensity, increase in temperature increase in rate. • At low light intensity, little change. • Above 30oC photosynthesis is reduced at both high and low light intensity- can you suggest why?

  9. Rate of photo synthesis High light intensity Low light intensity Temperature/oC Effect of temp. and light together

  10. What temperature is likely to be the optimum temperature at high light intensity? • What is likely to be the temperature at which photosynthesis stops? • Explain why this happens. Now do questions on p67

  11. Graphs and quiz • http://www.cix.co.uk/~argus/Dreambio/fertilisers%20and%20crops/limiting%20factors.htm

More Related