大象传媒

Plant pigment, light wavelength and photosynthesis rate

Absorption and action spectrum

The absorption spectrum (graph A) shows the wavelengths of light absorbed by the different pigments in a leaf. The action spectrum (graph B) shows how effective the different wavelengths of light are at photosynthesis.

Graph A

Absorption spectrum graph

Graph B

Action spectrum graph

Having multiple photosynthetic pigments increases the range of wavelengths of light that the plant can absorb and so increases the level of photosynthesis.

Investigating wavelength of light as a limiting factor of photosynthesis

As some wavelengths of light are absorbed more than others, this is a limiting factor for photosynthesis. This can be investigated in the lab.

Watch the videos below to see how these investigations can be carried out.

Related links