Chromatography?

Question

When doing using chromatography paper to separate colours of a leaf...

Why is acetone used to extract the pigments instead of water?

Leaves are often green - how can you account for this?

Of what use are the other photosynthetic pigments?

Answer 1

The photosynthetic pigments are not soluble in water but are very soluble in acetone.

Leaves are green because of chlorophyll, a green pigment.

The main other photosynthetic pigments in leaf photosynthesis are the carotenoids.  These are structurally similar, yet diverse, hydrocarbon molecules that harvest light in a region of the solar spectrum where chlorophyll absorption is relatively weak.  Hence, they are called "accessory" pigments and augment light absorption for photosynthesis.  Carotenoids also have very important functions in the molecular assemby of the light-harvesting apparatus and in protecting the apparatus from damaging effects of too much light.