Question : In the figure given below, theblack line (upper) indicates action spectrum for photosynthesis and the lighter line (lower) indicates the absorption spectrum of chlorophyll - a, answer the followings : (a) What does the action spectrum indicate ? How can we plot an action spectrum ?Explain with an example. (b) How can we derive an absorption spectrum reaction of photosynthesis, why do the acation spectrum and absorption spectrum not overlap ?

Question : In the figure given below, theblack line (upper) indicates

1.	Question : In the figure given below, theblack line (upper) indicates action spectrum for photosynthesis and the lighter line (lower) indicates the absorption spectrum of chlorophyll - a, answer the followings : (a) What does the action spectrum indicate ? How can we plot an action spectrum ?Explain with an example. (b) How can we derive an absorption spectrum reaction of photosynthesis, why do the acation spectrum and absorption spectrum not overlap ?
Answer» Solution :The effectiveness of various wavelenght of light can be noted down on photosynthesis and rate of photosynthesis can be decided. It is CALLED as action SPECTRUM of photo synthesis. (b) The effectiveness of various more lenghts of light can be noted dwon on definite pigments and the GRAPH which is made is called absorption spectrum of pigment. (c ) Chloropyll-a is responsible for light reaction of photosynthesis. But action specytrum and absorption spectrum do not overlap each other because chlorphyll-a is mainly a pigment associated with absorption of light energy. Moreover other pigments like chlorophyll-b , xanthophylls and caotenoids are accesory pigments. They also absorb light energy and transport that energy towards chlorophyll. In fact they are UNABLE to find expanded wavelenght which is useful is photosynthesis but they prevent chlorophyll-a from photooxidation.