Limiting Factors of Photosynthesis- Notes Pt2

Light, Temperature and Co2 affect the levels of GP, RuBP and TP

Light intensity if light is low then products in the light dependent reaction are reduced (ATP, NADPH) Therefore the conversion GP to TP is lower decreasing RuBp as well as GP concentration will rise as its still being synthesized

Temperature if this is low this can change the effect of rubisco and other enzymes by making products like GP slower than normal at very high temperatures enzymes can denature meaning no products are made at all

Carbon Dioxide Concentration if this lowers this will reduce the amount of GP as carbon is used to combine with RuBP therefore TP will also lower but RuBP concentration will rise

Limiting Factors can be investigated using pond weed

Pond weed can be used to measure that rate of photosynthesis by using light, temperature or Co2 the amount of oxygen produced correspond to the rate of photo synthesis.

Light intensity:

Test tube which contains pond weed is connected to a capillary tube full of water a tube of water is connected to a syringe.

For light intensity a light source is placed at a distance from the pond weed

and the weed is left for a set amount of time to photosynthesis so oxygen will be released and travel along the capillary tube a ruler measures the length the gas bubble has traveled away from the pond weed . This shows the amount of o2 produced

Other variables like Co2 and temp will need to be controlled then the experiment is repeated and mean is taken then the light source change distance for the same experiment again fro a range of meters.