The energetics of embryonic growth and development. I. Oxygen consumption, biomass growth, and heat production.

A quantitative phenomenological model to describe the relationships between biomass growth rate, oxygen consumption, and heat production in developing embryos has been developed and tested using a wide range of experimental data. The model employs generalized material and energy balances, principles of enzyme kinetics, and an overall metabolic model scheme based on known biochemical principles. The phosphorylation concentration ratio of ATP and ADP occurs naturally and becomes a significant parameter in the analysis. The model is applied to the growth of Escherichia coli, Oryzias latipes, chick spinal cord, and whole chicken eggs. Excellent agreement between the model and the experimental data is obtained. In a succeeding paper (Part II) environmental effects and growth efficiency are discussed.