absorption and limiting factors Flashcards
What colours are absorbed by chlorophyll?
Violet/Blue and red.
What is the optimum temperature for photosynthesis and why?
25oC, due to enzyme catalysed reactions in LIR, and higher temperatures closing the stomata to limit water loss, but also limiting CO2 absorption.
What are the limiting factors for photosynthesis?
CO2 concentration, temperature and light intensity.
What is the saturation point?
The point at which increasing the limiting factor has no effect, because another limiting factor starts to limit the rate of photosynthesis.
Why are there different pigments for photosynthesis?
To absorb more wavelengths of light
What are the 3 pigments involved in photosynthesis called?
Chlorophyll a and b, carotene
How can carbon dioxide concentration be increased in a greenhouse?
Burning small amounts of propane in a CO2 generator
How does an increased rate of photosynthesis affect yields?
Yields increase with rate of photosynthesis due to more glucose/hexose sugars being made so more biomass can be made/more growth.
What does it mean when a limiting factor graph levels off?
The amount of photosynthesis stays the same (it does not stop)
Why do leaves look green?
Green light is not absorbed, it is reflected
Water is needed for photosynthesis, why is it not considered a limiting factor for photosynthesis?
If water levels start to get low, the stomata close to limit water loss which would limit the diffusion of CO2 into the leaf so therefore CO2 would become the limiting factor.
. What is the compensation point?
The point at which the rate of photosynthesis and the rate of respiration are equal so no uptake of CO2 needs to occur because the CO2 produced in respiration provides it.
