TOPIC : 7.2
What is chromatography?
How many pigments are there in a plant?
How the different pigments in a plant can be separated?
APPARATUS : Please refer to the handout
MATERIAL : Please refer to the handout
METHOD : Please refer to the handout
Pigment front distance
Solvent front distance
Ratio of fronts
One of the requirements for the photosynthesis process to occur, the plant cells need sufficient light. Pigments are the substances that absorbed visible light. Different pigments absorb light of different wavelengths.
From the absorption spectrum of chlorophyll a, it suggests that blue and red light work best for photosynthesis.
There is a high degree correlation between the absorption spectra of leaf and the absorption spectra of chlorophyll a, chlorophyll b and carotene.
It is because those pigments are used to absorb the visible light for the leaf.
The phenomenon of capillarity is involved in this technique. The relative molecular mass of chlorophyll b is greater than chlorophyll a. Since it is lighter, chlorophyll b can cause more rise of the chromatography solvent in the microscopic spaces between the fibres of the chromatographic strip. So, this technique is very sensitive laboratory tool since it can differentiate existence pigments in a plant based on the molecular structure of the pigments.
From the experiment results, the Carotenoid has the lightest molecular weight. Its ratio of front is less than chlorophyll b, meaning that it can cause more raise between the microscopic spaces between the fibres of chromatographic strip. There is correlation between molecular weight and the manner in which the pigments separate. As the...