INFORMATION CONTENT AND BIOTOPOLOGY OF 

 THE CELL IN TERMS OF CELL ORGANELLES* 



Charles F. Ehret 



Division of Biological and Medical Research, 

 Argonne National Laboratory, Lemont, Illinois 



Abstract — The cell organelle is regarded as a characteristic structural unit of the organism 

 that bridges the gap between the molecular and cellular levels of organization. It may arise 

 from the nucleus as a primary organelle, or from other cytoplasmic organelles. A provisional 

 flow-diagram is presented, according to which specifically different cell structures are derived 

 from primary organelles by sequences of relatively simple events that involve two to five 

 binary decisions. 



I. INTRODUCTION 



A MAJOR limiting factor in estimates of information content of the organism 

 resides quite obviously in assumptions that are made regarding organization 

 of its component parts. Thus in terms of atoms, //(man) = 2 X 10^^, and 

 in terms of molecules //(man) = 3 X 10^^. The reduction in this second 

 Dancoff-Quastler estimate (1) of information content is permitted by 

 limitations placed upon possible positions of atoms as a result of the restricted 

 number of molecular configurations found in Hving systems. It follows that 

 if many of the molecular and macromolecular configurations that are theoreti- 

 cally possible actually occur in only a limited number of anatomical and micro- 

 anatomical (organellar) configurations, then a further reduction of this estimate 

 by several orders of magnitude is possible. In reductio ad absurdum the terms 

 might be alive or not, as Augenstine has suggested (2), and the information 

 content one bit or less; however, such a classification would be of more value to 

 exterminators than to biologists. 



The existence of such organelles as chromidia, micellae, bioplasts, etc., 

 that occupy in all cells a functionally meaningful position between the mole- 

 cular and gross anatomical levels of organization was long ago claimed by 

 some cytologists but denied by most (3). New evidence from electron and 

 phase contrast microscopy revives but considerably revises the earUer unifying 

 view; it allows for characterizable 'nuclear ambassadors' each equipped with 

 a versatile morphogenetic repertoire to roam the cytoplasm and serve the 

 structural and functional needs of the cell. While the evidence to date is far 

 from complete, its general implications are presented here. 



II. ORGANELLES AND PRIMARY ORGANELLES 



Firstly, we define and characterize organelles in the following manner: 

 1. Organelles are elements of unitization for the macromolecular species 

 of an organism: they occupy niches between the macromolecular and cellular 

 * Work performed under the auspices of the U.S. Atomic Energy Commission. 



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