From Molecules to Living Organisms : an Interplay between Biology and Physics : Lecture Notes of the Les Houches School of Physics

The aim of this book is to provide new ideas for studying living matter by a simultaneous understanding of behavior from molecules to the cell, to the whole organism in the light of physical concepts. Indeed, forces guide most biological phenomena. In some cases these forces can be well-described and thus used to model a particular biological phenomenon. This is exemplified here by the study of membranes, where their shapes and curvatures can be modeled using a limited number of parameters that are measured experimentally. The growth of plants is another example where the combination of physics, biology and mathematics leads to a predictive model. The laws of thermodynamics are essential, as they dictate the behavior of proteins, or more generally biological molecules, in an aqueous environment. Integrated studies from the molecule to a larger scale need a combination of cutting-edge approaches, such as the use of new X-ray sources, in-cell NMR, cryo-electron microscopy or single-molecule microscopy. Some are described in dedicated chapters while others are mentioned in discussion of particular topics, such as the interactions between HIV and host cells which are being progressively deciphered thanks to recent developments in various types of microscopy. All the concepts and methods developed in this book are illustrated alongside three main biological questions: host–pathogen interactions, plant development and flowering and membrane processes. Through these examples, the book intends to highlight how integrated biology including physics and mathematics is a very powerful approach.