What is the Difference Between Action Spectrum and Absorption Spectrum?
🆚 Go to Comparative Table 🆚The main difference between an action spectrum and an absorption spectrum lies in what they represent in the context of photosynthesis. Here are the key differences:
- Absorption Spectrum: This shows the wavelengths of light absorbed by each pigment, such as chlorophyll, in a plant. It is a graphical representation of the different wavelengths of light absorbed by different pigments and indicates the relationship between the quality of light and the absorbing capacity of pigments. The absorption of wavelengths of different pigments can be measured with a spectrophotometer.
- Action Spectrum: This shows the overall rate of photosynthesis at each wavelength of light. It is a graphical representation of the effectiveness of different wavelengths of light in photosynthesis and infers the relationship between photosynthetic activity in relation to different wavelengths of light. The action spectrum is studied in relation to oxygen evolved or carbon dioxide absorbed.
In summary, the absorption spectrum deals with the wavelengths of light absorbed by each pigment, while the action spectrum indicates the overall rate of photosynthesis at each wavelength of light and the effectiveness of different wavelengths in the process.
Comparative Table: Action Spectrum vs Absorption Spectrum
Here is a table summarizing the differences between the absorption spectrum and the action spectrum:
Absorption Spectrum | Action Spectrum |
---|---|
Shows the wavelengths of light absorbed by each pigment, e.g., chlorophyll | Shows the overall rate of photosynthesis at each wavelength of light |
Graphical representation of the different wavelengths of light absorbed by the different pigments | Graphical representation of the effectiveness of the different wavelengths of light in photosynthesis |
The absorption of wavelengths of different pigments can be measured with a spectrophotometer | The rate of photosynthesis is measured as the amount of CO2 fixation, oxygen production, or NADP+ reduction |
Indicates the relationship between the quality of light and the absorbing capacity of pigments | Indicates the relationship between photosynthetic activity in relation to different wavelengths of light |
Can be studied directly | Is studied in relation to oxygen evolved or carbon dioxide absorbed |
Both spectra display two main peaks: a larger peak at the blue region (~450 nm) and a smaller peak at the red region (~650 nm). They also have a trough in the green/yellow portion of the visible spectra (~550 nm). The action spectrum peak of chlorophyll is almost the same as that of the absorption spectrum, indicating that chlorophyll is the primary pigment in photosynthesis.
- Absorption Spectrum vs Emission Spectrum
- Emission vs Absorption Spectra
- Absorptance vs Absorbance
- Excitation vs Absorption
- Absorbance vs Transmittance
- Atomic Absorption Spectroscopy vs UV Visible Spectroscopy
- Absorbance vs Fluorescence
- Continuous Spectrum vs Line Spectrum
- Atomic Absorption vs Atomic Emission
- Flame Emission Spectroscopy vs Atomic Absorption Spectroscopy
- Absorption vs Adsorption
- Electromagnetic Radiation vs Electromagnetic Spectrum
- Optical Density vs Absorbance
- Emission vs Continuous Spectrum
- a Continuous Spectrum vs a Bright Line Spectrum
- Absorption vs Assimilation
- Prism Spectra vs Grating Spectra
- Molar Absorptivity vs Specific Absorbance
- Absorptivity vs Molar Absorptivity