(Created 2008-07-17.)

THEORETICAL BIOPHYSICS | TEK267 |

*Knowledge and understanding*

For a passing grade the student must

*Fundamentals of statistics and statistical molecular kinematics:* The student can describe and use statistical distributions, in particular the Gaussian distribution, average value and standard deviation. The student can describe and use the Boltzmann distribution in various applications.

*Brownian motion, random walks and diffusion:* The student can describe random walks and is able to derive their characteristic behaviour. The student can demonstrate how random walks give rise to the diffusion equation, and how diffusion is related to viscosity. The student can describe various biological applications of diffusion.

*Viscous media:* The student can explain the Reynolds number and Stokes' law, and describe various biological applications of viscous flows.

*Entropy, free energy and two-level systems:* The student can explain the concepts statistical weight and entropy and their relation. The student can describe free energy and calculate the behaviour of two-level systems.

*Entropic forces:* The student can explain the following concepts: osmotic pressure, hydrogen bonds, hydrophilic and hydrophobic groups.

*Chemical forces:* The student can explain chemical potential and describe chemical equilibrium. The student can describe how micelles are formed and is familiar with various applications.

*Macromolecules:* The student can describe the fundamental structure formation of proteins and DNA.

*Molecular mechanisms and machines:* The student can describe nerve signals or a molecular machine of his/her own choice, e.g. motor proteins or ion channels.

Typical problems that the student should be able to handle:

- Applications of diffusion (Fick's law and the diffusion equation).
- Viscous flow in vascular networks (Hagen-Poiseuille's law).
- Extension vs. force for chains of given length and persistence length (wormlike chains).

**Contents**

Cell composition and content; fundamentals of statistics and statistical molecular kinematics; Brownian motion, random walks and diffusion; viscous media; entropy, free energy and two-level systems; entropic forces; chemical forces; macromolecules; molecular mechanisms and machines.

**Literature**

As posted on our webpage and billboard.