372 



CHLOROPLASTS AND CHROMOPLASTS 



CHAP. 14 



only one-third to one-half the total leaf proteins are contained in the 

 ehloroplasts (one-half, if we assume Chibnall and Meyer's ratio of 

 chloroplasts : cytoplasm as 2 : 1 and one-third if we accept Menke's 

 ratio of 1 : 1). Granick (1938) and Galston (1943) found 30-40% of the 

 nitrogen in tomato, tobacco, and oat leaves to be associated with the 



Table 14.III 



Proteins and Lipoids in Different Parts of the Leaf 

 A. AFTER Chibnall (1939) 



B. AFTER MeNKE (1938) 



" Water-soluble fraction: organic matter, 57% (many flavones); inorganic, 43%. 

 ^ Contains chlorophyll (mostly chlorophyll a). 

 ' Depending on age of plant and time of year. 



