Where does photosynthesis take place?
Plants and algae can only carry out photosynthesis in the light.
Plants get carbon dioxide from the air through their leaves. The carbon dioxide diffuses through small holes in the underside of the leaf called stomata. (singular: stoma. plural: stomata)
The lower part of the leaf has loose-fitting cells, to allow carbon dioxide to reach the other cells in the leaf. This also allows the oxygen produced in photosynthesis to leave the leaf easily.
Carbon dioxide is present in the air we breathe, at very low concentrations. Even though it forms about .04% of the air, it is a needed factor in light-independent photosynthesis.
In higher concentrations, more carbon is incorporated into carbohydrate, therefore increasing the rate of photosynthesis in light-independent reactions.
Where does the carbon that is used in photosynthesis come from
Carbon dioxide is captured in a cycle of reactions known as the Calvin cycle or the Calvin-Benson cycle after its discoverers. It is also known as just the C3 cycle. Those plants that utilize just the Calvin cycle for carbon fixation are known as . Carbon dioxide diffuses into the stroma of chloroplasts and combines with a five-carbon sugar, ribulose1,5-biphosphate (). The enzyme that catalyzes this reaction is referred to as , a large molecule that may be the most abundant organic molecule on the Earth. This catalyzed reaction produces a 6-carbon intermediate which decays almost immediately to form two molecules of the 3-carbon compound 3-phosphoglyceric acid (). The fact that this 3-carbon molecule is the first stable product of photosynthesis leads to the practice of calling this cycle the C3 cycle.
Photosynthesis uses carbon dioxide with water to make glucose
In many ways, carbon dioxide has been mischaracterized because of its association with greenhouses and global warming. But in fact, carbon dioxide is a naturally occurring gas with many useful functions. From carbonated drinks, to fire extinguishers, to inflatable life jackets, carbon dioxide has a number of useful rolls in our modern world. But more importantly, carbon dioxide is essential for life on our planet, because it is required for the photosynthesis that plants utilize to convert energy into the food we eat.
How does carbon affect photosynthesis?
While carbon dioxide is not a poison, it can be dangerous in high concentrations or enclosed environments where it displaces oxygen. But in the open air, carbon dioxide dissipates quickly, making it an unlikely risk to public health.