Page 98 - Biology - XII

String
Stand

Clip
Beaker
Filter paper strip
Coloured bands

Chlorophyll solution

Fig. 3.1: Separation of chlorophyll solution by capillary analysis

2. Hang a strip of fi lter paper by a burette stand such that its (fi lter strip) lower edge dips or touches the
chlorophyll solution in a beaker after a few minutes.

Results
1. The fi lter paper absorbs the solution and the yellow zone (chiefl y of carotenoids) proceeds/advances
the green solvent.
2. At the point of contact, green pigments chlorophyll (a) and (b) are fi xed.

3. Keen observation will show that a bluish-tinted on the upper edge of the green zone is seen. It is of
chlorophyll (a) and lower yellowish green portion is of chlorophyll (b).

Discussion
1. Chlorophyll solution gets separated into various colour zones, viz.

(i) Yellow zone of carotenes. (iii) Yellowish green zone of chlorophyll B.
(ii) Bluish zone of chlorophyll A.
2. Dry the fi lter paper strip in air and use it for your record fi le.

Conclusion
Chlorophyll solution has diff erent pigments.

B. SEPARATION OF PLASTIDIAL PIGMENTS BY BENZENE
Objective
To separate various plastidial plant pigments by benzene.

Materials Required
Alcoholic extract of green leaves, benzene, test tube, and water

Procedure
1. In a clean and dry test tube, take 5 ml of the alcoholic extract of green leaves. Add 5 ml of benzene and
a little water (1 ml).

2. Put your thumb at the mouth of the test tube and invert the contents many times up and down.

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