Question

Differentiate between the absorption spectrum and the action spectrum.

Answer 1

Hint:Absorption spectrum deals with wavelengths of light absorbed by each pigment whereas the action spectrum indicates the overall rate of photosynthesis at each wavelength of light.

Complete Answer:
In this question, we will be dealing with the key differences between the absorption spectrum and the action spectrum. Using a table lets list the key differences between them,

Absorption spectrum	Action spectrum
It shows the wavelengths of light absorbed by each pigment for, e.g., chlorophyll	It shows the overall rate of photosynthesis at each wavelength of light.
It is the graphical representation of the different wavelengths of light absorbed by the different pigments in the leaf during the process of photosynthesis.	It is the graphical representation of the effectiveness of the different wavelengths of light in photosynthesis.
It infers the relationship between the quality of light and the absorbing capacity of pigments.	It infers the relationship between photosynthetic activity in relation to different wavelengths of light.
It can be studied directly.	It is studied in relation to oxygen evolved or carbon dioxide absorbed.
The absorption of wavelengths of different pigments can be measured with a spectrophotometer.	The amount of photosynthesis can be measured with the amount of carbon dioxide fixation, oxygen production, NADP Reduction, etc.

Note: It is to be noted that maximum absorption takes place in the blue region but maximum photosynthesis takes place in the red region.