Absorption and Action Spectrum

Absorption and Action Spectrum

Absorption Spectrum

• The absorption spectrum of a pigment represents the wavelengths of light it absorbs most effectively.
• Different pigments have distinct absorption spectra due to variations in their molecular structures.
• In photosynthesis, chlorophyll a and chlorophyll b are the primary pigments with unique absorption spectra.
• Chlorophyll a primarily absorbs red and blue light, while chlorophyll b extends the range by absorbing light in other wavelengths.

Action Spectrum

• The action spectrum illustrates the effectiveness of various wavelengths of light in driving a specific biological process, like photosynthesis.
• It compares the rate of photosynthesis under different wavelengths of light.
• The action spectrum for photosynthesis closely matches the absorption spectra of chlorophyll a and chlorophyll b.
• This alignment suggests that chlorophyll pigments are essential for photosynthesis since they absorb light in the wavelengths that are most effective for this process.

Importance

• Understanding absorption and action spectra helps explain how photosynthetic organisms capture and utilise light energy.
• It provides insights into the relationship between pigment properties and photosynthetic efficiency.

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Absorption and Action Spectrum

Summary

• Absorption spectrum indicates the wavelengths of light a pigment absorbs effectively.
• Chlorophyll pigments have unique absorption spectra.
• Action spectrum demonstrates the effectiveness of different wavelengths of light in driving biological processes.
• The action spectrum for photosynthesis corresponds closely to the absorption spectra of chlorophyll pigments, highlighting their pivotal role in photosynthesis.