THE CYTOPLASM 229 



of small particles derived from fragmentation of the sarcosomal membrane. 

 The latter results are strikingly similar to those obtained by the writers 

 in studies of disintegrated liver mitochondria.^^ ■^'' 



A few studies of the fractions isolated from brain^*^-^" and from kid- 

 ney^^'^"- have indicated that the mitochondria of these tissues are also 

 generally similar in their biochemical properties to the mitochondria of 

 liver. Brody et al.,^^'' however, obtained a much higher recovery of DPN- 

 cytochrome c reductase in brain mitochondria than was found in the 

 corresponding liver fraction (Table II). 



Recently, some very interesting data have been obtained by Watanabe 

 and Williams,''** Sacktor,'** and Levenbook^'** in studies of sarcosomes iso- 

 lated from the flight muscle of certain flies. A review on the subject has 

 been published by Levenbook.'*^ These relatively large (2.5 m in diameter) 

 bodies account for approximately 33 % of the entire flight muscle dry 

 weight, can be isolated by a relatively simple procedure, and possess most, 

 if not all, of the cytological characteristics of the mitochondria of the 

 cells of vertebrates. There is, furthermore, a remarkable similarity in the 

 enzymic properties of the insect muscle sarcosomes and of liver mito- 

 chondria.'** ''^^''^ This is particularly evident in Sacktor's'*^ investigation 

 of adenosinetriphosphatase and adenylate kinase. His observations are 

 almost identical to those made by Kielley and Kielley"'*''^' on isolated 

 liver mitochondria. 



As indicated previously, Andresen et al.*" found that succinic dehydro- 

 genase is probably localized in the mitochondria of the amoeba Chaos 

 Chaos, and Recknagel®^ found that cytochrome oxidase is concentrated in 

 the mitochondria of frog eggs. 



A number of studies dealing with the properties of cell fractions isolated 

 from plant tissues have been published in recent years. '*^''^^''" In general, 

 the data suggest that the metabolic role of plant mitochondria is basically 

 similar to that of the mitochondria of animal tissues. It has also been 



66 T. M. Brody and J. A. Bain, J. Biol. Chem. 195, 685 (1952). 

 " T. M. Brody, R. I. H. Wang, and J. A. Bain, J. Biol. Chem. 196, 821 (1952). 

 " B. Sacktor, /. Gen. Physiol. 36, 371 (1953). 

 " H. A. Stafford, Physiol. Plantarum 4, 696 (1951). 

 «" J. H. McClendon, Am. J. Botany 39, 275 (1952). 

 «i J. H. McClendon, Am. J. Botany 40, 260 (1953). 

 «2 C. R. Stocking, Am. J. Botany 39, 283 (1952). 

 «3 P. Saltman, J. Biol. Chem. 200, 145 (1953). 



" H. G. duBuy, M. W. Woods, and M. D. Lackey, Science 111, 572 (1950). 

 6* J. Bonner and A. Millerd, Arch. Biochem. and Biophys. 42, 135 (1953). 

 «6 A. Millerd, Arch. Biochem. and Biophys. 42, 194 (1953). 



" A. Millerd, J. Bonner, B. Axelrod, and R. S. Bandurski, Proc. Natl. Acad. Sci. 

 U. S. 37, 855 (1951). 



