Abstract:
Historical background and organisation of the present work: Cytologists have appreciated for many years that the cell is not a homogeneous mass of protoplasm but contains structures that can be observed and identified by light or electron microscopy. It has become increasingly apparent to biochemists that a mixture of enzymes, substrates and products in a single phase could hardly carry out the many reaction sequences that must be involved in the metabolic transformations conducted by the cell. Thus attention has been increasingly directed to the study of the discrete units of the cell with respect to chemical constitution and biological function. The pioneering studies of Bensley and Hoerr (1934) and Claude (1946) on cellular fractionalism have led to what is now a powerful approach to the study of living cells - smashing them and studying the pieces. The first objective of cellular fractionation is to find out what reactions take place and what compounds occur in the various isolated systems. A second objective is to reassemble the pieces and relate their activities in various combinations to the activities of the whole cell.
