3. limiting factors in photosynthesis Flashcards
optimum conditions
high light intensity of a certain wave length
light in needed to provide energy for the LDF - the higher the intensity of light the more energy it provides
only certain wavelengths of light are used.
photosynthetic pigments chlorphyll a, chrlorophyll b and carotene only absorb
red an blue light in sunlight (green is reflected which is why plants look green)
optimum conditions
temperature around 25 C
photosyntheiss involves enzymes e.g. aTP synthase, rubisco. if temperature falls below 10 C the enzymes become inactive but if temperature is more than 45 C they may denature
high temperatures = stomata close to acoid loosing too much water. photosynthesis slows bevause less CO2 enters leaf when stomata close
optimum conditions
CO2 at 0.4%
CO2 makes up 0.04 of the gases atmosphers
increasing this to 0.4% gives a higher rate of photosynthesis but any higher and the somata start to close
what can limit photosynthesis
light, temperature, CO2
the saturation point is where
a factor is not longer limiting the reaction - something else has become the limiting factor qwqwqwqw
agricultural growers can create optimum conditions in glasshouses in the following ways
CO2 Conc
CO2 is added e.g. by burning a small amount of propane in a CO2 generator
agricultural growers can create optimum conditions in glasshouses in the following ways
light
light can get through the glass
lamps provide light at night time
agricultural growers can create optimum conditions in glasshouses in the following ways
temperature
glass houses trap heat energy from sunlight which warms the air
heaters and cqwooling systems can also be used to keep a constant temperature
air circulation systems make sure the temqwpreature is even throqwughout glasshouse
alternative to growing plants in glass houses
in polytunnels (tunnels made of polyethene under which plants can be grown)qw
