# Biophysics

From PGSC Wiki

The format of the exam has changed in Fall 2011. Students will still be given a problem by their advisors a week in advance. But the problem will serve as a warm up and occupy only about 30 mins of the roughly 2h exam. The examiners will ask broad questions from all of biophysics including order of magnitude estimations, simple experimental questions etc. Please have a look at the attached document from Jeff Gore and the reflections of various students for help preparing for the exam. Some topics and questions that were asked in the past:

- Statistics of the number bacteria surviving antibiotic selection through the appearance of benefitial mutations.
- Notion of effective temperature for the expression level of a gene in a network.
- Random walk models of bacterial chemotaxis.
- Models of microtubules growth.
- Models of molecular motors.
- Thermodynamics of a DNA zipper.
- Statistical mechanics of polymers. Force-extension curves. Notion of persistence length.
- Random Energy Model for protein structure.
- Energy and forces involved in DNA packing.
- Fluid dynamics. Life at low Reynolds numbers, reversibility of the equations of motion. Computation of the drag force for simple geometries (sphere).
- Diffusion equation.

## Resources[edit]

- Since 2011 changed Exam format and preparation advice by Jeff Gore : View
- Part 3 Reflections by 2011 Students-including how to prepare for the exam, what to expect in the exam :

- Part 3 Reflections by 2009 Students-including how to prepare for the exam, what to expect in the exam : View