THE RELATION OF ENZYMATIC ADAPTATION TO THE METABOLISM OF ENDOGENOUS AND EXOGENOUS SUBSTRATES.

The source of energy for enzymatic adaptation has been investigated. Aerobically, it is found that the endogenous carbohydrate reserves may be used as such a source. In cells depleted of their reserves, the adaptive substrate itself can be oxidized even while it cannot be fermented, and so can serve as a source of energy for the adaptation to a fermentative mode of utilization.

MAXIMA IN RATE-CONCENTRATION CURVES AND THEIR RELATION TO THE STRUCTURAL ASPECTS OF CELLULAR METABOLISM.

1. Reproducible maxima are exhibited in the rate-concentration curves obtained by studying the effects of ethyl- and phenylurethanes on regeneration rates of hydranths in Tubularia. 2.