Get Answers to all your Questions

header-bg qa

In the figure given below, the black line(upper) indicates action spectrum for photosynthesis and the lighter line(below) indicates the absorption spectrum of chlorophyll a, answer the followings:

a. What does the action spectrum indicate? How can we play an action spectrum? Explain with an     example.

b. How can we derive an absorption spectrum for any substance?

c. If chlorophyll-a is responsible for the light reaction of photosynthesis, why do the action spectrum and      absorption spectrum not overlap?

Answers (1)

a. The action spectrum indicates the process and rate of photosynthesis. This rate is calculated by the amount of oxygen released. An action spectrum can be drawn by keeping the amount of released oxygen on the y-axis and the wavelength of light on the x-axis. The pigments which absorb the different wavelengths of light will be indicated the graph. The above graph, however, shows chlorophyll.

b. An absorption spectrum for any substance can be drawn by plotting the absorption of various light wavelengths by different pigments like chlorophyll a or chlorophyll b.   

c. The action spectrum does not overlap because of the presence of other pigments. These other pigments are called accessory pigments and help in harvesting solar energy. As a result, the spectrum is always at a high level as compared to the absorption spectrum. 

Posted by

infoexpert23

View full answer