摘要：

The chapter discusses the enzymatic alteration of the macromolecular structure. These enzymes that intervene in the shaping of the structure of macromolecules are, therefore, probably, relatively, young components of the processes that have been superimposed on more primitive mechanisms, just as the mechanism of speciation must be an ancillary development on archetypal processes. The rapidly increasing number of enzymes whose function, either is or on theoretical grounds, appears to be the alteration of macromolecules that poses numerous challenging problems to the biochemist. First, there are questions, concerning the mechanism of the action of the enzymes, already known. Second, lots of experience in the studies of the mechanism of enzyme action are limited to the systems, in which the substrates are small molecules. While progress in this area is being made at an accelerated pace, the answers to many of the questions on the fine mechanisms of reactions are less than satisfying. In addition to those examples of the alteration of macromolecules enumerated in this chapter, others come readily to mind. The insertion of glucose into specific positions in some collagens, the interaction of the components of the blood-clotting mechanism, the conversion of zymgens to active enzymes, all indicate highly specific macromolecular alterations beyond the zone of possible direct coding for them in the deoxyribonucleic acid (DNA).

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