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Monogalactosyl Diacylglycerol is a glycolipid and contain a high proportion of polyunsaturated fatty acid substituents and form hexagonal structure when dispersed in excess water. Catalytic hydrogenation of this Lipid in the presence of catalyst completely saturates the hydrocarbon chains and the Lipid forms typical open sheet bilayer structure in water at 20?C. Binary mintures of native and hydrogenated Lipid tend to phase-separated at 20?C, our results which was obtained by electron microscope reveals lamellar phase Lipid indispersed with regions of hexagonal structure and the proportion of each reflect the composition of mixture. Monogalactosyl Diacylglycerol is one of those Lipids, which present in high amount in thylakoid membrane of chloroplast. This membrane and others they go through this kind transformation in their Lipid structure to enable the biochemical physiological functions of the cells.