IB Biology: Photosynthesis And Cellular Respiration
At first sight it seems that the one process is simply the reverse of the other. In fact these equations are merely ‘balance sheets’ of the inputs and outputs. Photosynthesis and respiration occur by different pathways with many enzymes unique to one or the other pathway. And of course, photosynthesis is an anabolic process, whereas respiration is a catabolic one.
Both Photosynthesis and Cellular Respiration provide power ..
As we can see, there is a close relationship between the action spectrum and absorption spectrum of photosynthesis. There are many different types of photosynthetic pigments which will absorb light best at different wavelengths. However the most abundant photosynthetic pigment in plants is chlorophyll and therefore the rate of photosynthesis will be the greatest at wavelengths of light best absorbed by chlorophyll (400nm-525nm corresponding to violet-blue light). Very little light is absorbed by chlorophyll at wavelengths of light between 525nm and 625 (green-yellow light) so the rate of photosynthesis will be the least within this range. However, there are other pigments that are able to absorb green-yellow light such as carotene. Even though these are present in small amounts they allow a low rate of photosynthesis to occur at wavelengths of light that chlorophyll cannot absorb.
The processes of photosynthesis and cellular respiration are linked to each other, however, they also differ in a couple of pointers. It is important that one understands this difference.