Biophysics of Proteins, DNA and Membranes (Membran)

Course content

This course is the second introductory biophysics course and focuses on the thermodynamics of biological systems. These are in particular biological macromolecules (proteins and nucleic acids), membranes, and the interactions between them. This includes a brief introduction into concepts of thermodynamics and statistical thermodynamics. Topics are (amongst others) protein binding, protein and DNA folding, cooperative transitions (helix coil transitions, denaturation, allosteric reactions), cold denaturation, etc. The second major topic is biological membranes, which are those components of a biological cell that separate the functional units and form the spacial boundaries of the organelles. The major building block is the lipid bilayer into which proteins are embedded. Membranes maintain the chemical potentials of the cell components, and regulate transport. The membrane proteins have many catalytic and transport properties. The membranes themselves display all kinds of interesting physical properties: They can melt and they are characterized by elastic constants, which are important for membrane fusion and structural changes and depend on the melting. Furthermore, membranes may be permeable to certain molecules and they form lateral domains of their components, which are highly discussed in the context of cell signaling. We will introduce into the thermodynamics of membranes, their electrostatics, the hydrophobic effect, elastic theory and lipid-protein interactions.


BSc Programme in Nanoscience
BSc Programme in Physics
MSc Programme in Physics w. minor subject

Learning outcome

In order to pass the course the student should be able to:

  • Explain the basic concepts of statistical thermodynamics and its application to cooperative transitions, including enzyme activity and allosteric reactions
  • Analyze heat capacity profiles of protein folding and membrane melting
  • Explain structural biology methods such as x-ray diffraction and nuclear magnetic resonance, and the major structural features of proteins, DNA and membranes
  • Describe the phases of membranes, cooperative transitions and the nature of the fluctuations.
  • Derive simple phase diagrams from ideal solution theory or regular solution theory, including the lever rule and Gibbs’ phase rule
  • Explain the origin of the action of anesthetics on membranes
  • Derive the Guy Chapman theory for the electrostatic potential of membranes


  • Understand the basic thermodynamics laws, the role of entropy in defining the states biomolecules, mass action law, van’t Hoff law
  • Understand the role of water in biology, including the Debye-Hückel theory, the hydrophobic effect and the cold unfolding of proteins

The course builds upon the previous biophysics course, broadening the students’ scope of the subject, and gives a background for following more advanced, specialized courses.

Lectures and excersices

Handouts are sufficient. Recommended reading: C.R. Cantor & P.R. Schimmel, Biophysical Chemistry, W.H. Freeman, N.Y., 1980 T. Heimburg, Thermal Biophysics of Membranes, Wiley-VCH, Weinheim 2007

The student should have taken an introductory course on biophysics.

7,5 ECTS
Type of assessment
Oral examination, 25 min
No preparation time.
Without aids
Marking scale
7-point grading scale
Censorship form
No external censorship
More internal examiners
Criteria for exam assessment

See "Learning Outcome"

Single subject courses (day)

  • Category
  • Hours
  • Lectures
  • 42
  • Theory exercises
  • 14
  • Exam
  • 0,5
  • Preparation
  • 149,5
  • English
  • 206,0