Fluctuations, diffusion and information processing in cells

PONCE DAWSON, SILVINA

Oeiras

Otro; Programa de Doctorado en Biologia Integrativa y Biomedicina; 2014

Instituto Gulbenkian

Information transmission in cells occurs quite accurately even though concentration changes are ``read'' by individual target molecules. In most cases, the acting molecule diffuses and eventually binds to the receptor that generates a response. In this way, the final behavior of the cell depends on the acting molecule concentration. Even though the acting molecule diffuses, the fact that it binds to other elements of the cell affects its transport. In some circumstances the resulting net transport is diffusive but with an effective (concentration dependent) instead of free diffusion coefficient. In this lecture I will discuss free and effective diffusion. I will focus on the effects that reactions have on the net transport of molecules, on the transport rates that are inferred from optical experiments and on the time it takes for a receptor to obtain an accurate estimate of its agonist concentration.