Energetics of Biological Systems

ongoing

All living systems function out of thermodynamic equilibrium and require a continuous supply of energy. To understand how cells and organisms function, we need to determine how metabolic energy is partitioned among the complex array of cellular processes that are necessary for life at any scale, from isolated biochemical networks to quiescent and highly proliferative cells to organismal growth and development. To investigate the energetics of living systems, I established calorimetry to measure the energy exchanged in the form of heat between biological systems and their environment. By combining these measurements with specific perturbations, I have shown that the energetic costs associated with a given biological process can be calculated, and thus, provides a means towards understanding the energetics of biological systems. This proposal aims to understand the energetic costs of accurate cell signaling, and of homeostasis, proliferation, and growth of cells and organisms. It will further investigate how these biological systems are governed by energetic trade-offs. First, the trade-off between energy dissipation and accuracy of biochemical signaling pathways. Second, the trade-off between power and yield during cell growth and organismal development. Specifically, I will: 1) Develop approaches to quantify the overall energetics of biological systems 2) Elucidate the role of energy dissipation on the accuracy and reproducibility of cell cycle signaling 3) Determine how energetics drive embryonic development and cell growth This work will overcome the current lack of non-invasive techniques to quantitatively measure metabolic rates, especially rates of energy conversion and dissipation in biological systems. The results will yield quantitative thermodynamic data needed to determine the energetics of biological systems and will be essential for kinetic growth studies of normal and diseased systems.