Radiation In the total electromagnetic spectrum,visible light is the smallest part. The entire life on earth depends on light and is the driving force for all organisms. Plants have natural potential to utilize solar energy directly. In the given picture electromagnetic radiation spectrum and components of visible spectrum are mentioned.
The wavelength of solar radiation which reaches the earth . . Chlorophyll Chlorophyll 'a' is the primary pigment which acts as a reaction centre and all other pigments act as accessory pigments and trap solar energy and then transfer it to chlorophyll 'a'. Chlorophyll molecules have a tadpole like structure.
It consists of Mg-Porphyrin head (Hydrophilic Head) and (Lipophilic tail) Phytol tail. The Porphyrin head consists of four pyrrol rings linked together by C-H bridges. Each pyrrole ring comprises of four carbons and one nitrogen atom. Porphyrin ring has several side groups which alter the properties of the pigment.
Different side groups are indicative of various types of chlorophyll. The Phytol tail made up of carbon alcohol is attached to carbon of the Pyrrole ring IV. It has a long propionic acid ester bond. Long lipophilic tail helps in anchoring chlorophyll to the lamellae.
. . Carotenoids Figure . : Changes in Fruit colour due to difference in pigmentation Carotenoids are yellow to orange pigments, mostly tetraterpens and these pigments absorb light strongly in the blue to violet region of visible spectrum.
These pigments protect chlorophyll from photo-oxidative damage. Hence, they are called as shield pigments . These pigments absorb light and transfer these to chlorophyll. Almost all carotenoid pigments have carbon atoms.
Ripening of fruits, floral colours and leaf colour change during autumn is due to Carotenoids (Carotene and Xanthophyll) (Figure . ). i. Carotenes: Orange, Red, Yellow and Brownish pigments, hydrocarbons (Lipids) Figure .
: Electromagnetic Spectrum Separation of Chlorophyll pigments by paper Chromatography method Step . Extract chlorophyll pigment from the leaves using % Acetone. Step . Allow to concentrate by evaporation.
Step . Apply few drops on one end above cm from the edge of a chromatographic paper. Step . A