Biochemical Basis of Immaturity

Abstract

Development represents a group of time-dependent phenomena, all of which participate in the growth of the organism. These processes as typified by enzymatic activity, are either progressive, abrupt, or transient. Protein synthesis or activation may be causative and subject to various forms of regulation. The utilization of this discontinuous biochemical information for interpretation of developmental physiology is currently difficult, even though these molecular variations are reflected by performance of the organ. An imaginative hypothesis for the variable genetic expressivity encountered during development was formulated by Jacob and Monod. It is customary to designate perinatal processes as immature. If "immaturity" is meant to connote an impairment in function, those instances where function of an organ or an enzyme is more efficient or active in early life would refute such a generalization. It is reasonable to consider the immature individual as one not fully developed, but it is inaccurate to extrapolate function of the adult to that of the young. Our knowledge of development will increase only from investigations derived from time-dependent phenomena.