Photosynthesis: the chemical process where plants use light energy to produce glucose (food)
carbon dioxide + water ---------light energy--------> glucose + oxygen
- light energy is absorbed by green chlorophyll found in plant cells
- this energy is used to convert co2 (air) and h2o (soil) into sugar (glucose)
- o2 is released as a waste/by product
Factors that may limit the rate of photosynthesis are:
Until approx 45*, the temperature & rate of photosynthesis increases. Temperature is the limiting factor.
Aroud 45*, the rate falls to 0, enzymes controlling photosynthesis denature.
As light intensity increases, so does the rate of photosynthesis. It's the limiting factor. At a certain point, the rate of photosynthesis plateaus.
An increase in light intensity has no further effect - it's no longer the limiting factor.
CARBON DIOXIDE CONCENTRATION
As the co2 concentration increases, so does the rate of photosynthesis. Co2 is the limiting factor. At a certain point, the rate of photosynthesis plateaus.
An increase in co2 concentration has no further effect - it's no longer the limiting factor.
Greenhouses may be used to control the rate of photosynthesis. This can result in plants growing more quickly + becoming bigger and stronger.
GLUCOSE PRODUCED IN PHOTOSYNTHESIS:
-Converted into insoluble starch for storage in stem, leaves or roots
Plants can store large amounts of starch in their cells w/o having a large affect on the water balance of the plant
-Cellulose for cell walls
-Lipid, fats, oils for storage
-Combines with nitrates to make amino acids which are used to make proteins. W/o this - stunted plant growth
Plants need mineral ions -- nitrates&magnesium-- which they absorb from the soil through their roots.
Magnesium is needed for chlorophyll production. W/o - yellow leaves.