Light Absorption and Pigments in Photosynthesis
This page delves into the intricate details of how leaves absorb light for photosynthesis and the pigments involved in this process. It explains the fate of light hitting a leaf and the various pigments responsible for light absorption.
When light hits a leaf, it can be absorbed for photosynthesis, reflected, or transmitted. The main pigments found in leaves are chlorophyll a, chlorophyll b, and carotenoids. These pigments have different absorption spectra, allowing plants to utilize a broader range of light wavelengths.
Vocabulary: Absorption spectrum - A graph showing the range of light wavelengths absorbed by different pigments.
The page also introduces the concept of thin-layer chromatography, which is used to separate and identify different pigments. The Rf value, which represents the ratio of the distance traveled by the pigment to the distance traveled by the solvent, is explained.
Definition: Rf value = distance traveled by pigment / distance traveled by solvent
An action spectrum is presented, showing how effective different wavelengths of light are for photosynthesis. This spectrum reveals that chlorophyll a absorbs red and violet light best, chlorophyll b absorbs blue light best, and carotenoids absorb blue-green light.
Highlight: The presence of multiple pigments allows plants to absorb a wider range of light wavelengths, enhancing their photosynthetic efficiency.
