INVESTIGADORES
MAYORGA Luis Segundo
artículos
Título:
Molecular thermodynamics for cell biology as taught with boxes.
Autor/es:
MAYORGA, LS; LÓPEZ, MJ; BECKER, WM
Revista:
CBEÂLIFE SCIENCES EDUCATION
Editorial:
AMER SOC CELL BIOLOGY
Referencias:
Año: 2012 vol. 11 p. 31 - 38
ISSN:
1931-7913
Resumen:
Thermodynamic principles are basic to an understanding of the complex fluxes of energy and information
required to keep cells alive. These microscopic machines are nonequilibrium systems at the
micron scale that are maintained in pseudo-steady-state conditions by very sophisticated processes.
Therefore, several nonstandard concepts need to be taught to rationalize why these very ordered
systems proliferate actively all over our planet in seeming contradiction to the second law of thermodynamics.
We propose a model consisting of boxes with different shapes that contain small balls
that are in constant motion due to a stream of air blowing from below. This is a simple macroscopic
system that can be easily visualized by students and that can be understood as mimicking the behavior
of a set of molecules exchanging energy.With such boxes, the basic concepts of entropy, enthalpy,
and free energy can be taught while reinforcing a molecular understanding of the concepts and
stressing the stochastic nature of the thermodynamic laws. In addition, time-related concepts, such
as reaction rates and activation energy, can be readily visualized. Moreover, the boxes provide an
intuitive way to introduce the role in cellular organization of information and Maxwells demons
operating under nonequilibrium conditions.