Chloroplast Substance of Spinach Leaves

Abstract

Prepns. of chloroplast substance isolated by fractional centrifugation showed less protein contamination than when flocculation with CaCl2 or freezing was used. The chloroplast substance of spinach leaves contains about 54% protein (N X 6.25), 34% lipoid, 5% chlorophyll and 7% ash. About 11% of the total N is found in the lipoid fraction and <1/3 of this lipoid N is accounted for by chlorophyll. The data indicate a ratio of 9 parts of chlorophyll per 100 parts protein in the chloroplast substance.