Page 111 - Medicinal Plants_PharmD general

II. Proteins

Proteins are nitrogenous organic compounds. They are
macromolecule (30000-50000) produced by the living cells, these
macromolecules are biopolymers composed of distinct monomers units
which are the L-aminoacids.

Porteins are stored by the plants usually in form of amorphous
masses or small particles called aleurone grains. They are small solid
protein particles occurring in the seed and measuring 20 12-m.

Amino acid Peptide

The typical aleurone grain (Figure 34) consists of:
(1) Amorphous ground substance
(2) Crystalloids.
(3) Globoids.

Figure 34. Aleurone grain
Ground substance: It is an amorphous protein which is soluble in water.
Grystalloid: It is formed of albumin which is hardly soluble in water. It is
stained brown with iodine solution, yellow with picric and red with
Millon’s reagent.
Globoid: It consists of globin combined with calcium and magnesium salts
of inositolphosphoric acid. It is insoluble in water.

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