sábado, 21 de setembro de 2013

Leaf Colour Chart

A sure sign of the onset of autumn can be seen in the leaves of trees. During the spring and summer the leaves have served as factories where most of the foods necessary for the tree's growth are manufactured.
The process, known as photosynthesis, takes place in the leaf in numerous cells containing chlorophyll a and b. Chlorophyll a molecules absorb light at a wavelength of 400-500nm, while chlorophyll b absorbs light in the 550-700nm as a result, the green spectrum is reflected and this is what we see. Along with the green pigment are yellow to orange pigments; carotenes and xanthophyll, however most of the year these colours are masked by great amounts of chlorophyll. 

Sem comentários: