What is the difference between an action and absorption spectrum? (We're talking about photosynthesis and the colors absorbed and such)
The difference between an action spectrum and an absorption spectrum lies in their respective roles in the study of photosynthesis.
1. Absorption Spectrum: An absorption spectrum refers to the wavelengths of light that a certain pigment or compound is capable of absorbing. In the context of photosynthesis, pigments such as chlorophyll and carotenoids in plants possess unique absorption spectra. These pigments selectively absorb certain wavelengths of light, while reflecting or transmitting others. The absorbed light energy is used to power the process of photosynthesis.
To determine an absorption spectrum, you would need to perform spectrophotometry. This involves measuring the amount of light absorbed by a pigment at different wavelengths. By plotting the data obtained, you can create an absorption spectrum that shows the wavelengths that are absorbed most effectively by the pigment.
2. Action Spectrum: On the other hand, an action spectrum describes the efficiency of photosynthesis at different wavelengths of light. It shows the rate or extent of photosynthesis as a function of light wavelength. The action spectrum provides insights into which wavelengths of light are most effective in driving the process of photosynthesis.
To determine an action spectrum, you would need to measure the rate of photosynthesis at various wavelengths of light. This can be achieved by using different light filters or monochromatic light sources and measuring the oxygen production or carbon dioxide uptake of a plant. The action spectrum is then created by plotting the photosynthetic rate versus the corresponding wavelengths of light.
In summary, the absorption spectrum focuses on the wavelengths of light absorbed by pigments, while the action spectrum examines the effectiveness of different light wavelengths in driving photosynthesis. The absorption spectrum helps determine which wavelengths a pigment can absorb, while the action spectrum reveals how efficiently photosynthesis occurs at different wavelengths of light.