Lecture 9

Lectures: 1 | 2 | 3 | 4-5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 15 | 16 | 17 | 19 | 20 | 21 | 22 | 23 | 26

Electrostatic Interactions

1. Ionic Solutions:
   • Why do Electrolytes Dissociate (Ionize) in Water?
   • The Bare Coulomb Interaction and the Bjerrum Length (Lecture Notes, Page 1 (GIF))
   • Acids, Bases, and Salts
   • The Importance of Coulomb Repulsion in Biological Systems
   • Macroions, Counterions, Salt Ions
   • Restricted Partition Function (Lecture Notes, Page 2 (GIF))
2. Statistical Treatments of Ionic Solutions:
   • 'Mean-field' Potential and Charge Density via the Self-consistent Poisson-Boltzmann Equation (Lecture Notes, Page 3 (GIF))
   • Dissociation of a Charged Membrane (Lecture Notes, Page 4 (GIF))
     • Solution of the 1d Equation
     • The Gouy-Chapman Layer
   • Screening in Salt Solutions (Lecture Notes, Page 5 (GIF))
     • Linearized Poisson-Boltzman
     • Debye-Hückel Screening
   • Importance of Fluctuations; Like Charges can Attract (PDF)
3. Electrostatics of Charged DNA
   • Manning Condensation (Lecture Notes, Page 6 (GIF))
   • Bending Cost of a Charged Rod [Odijk, Skolnik, Fixman (OSF)] (Lecture Notes, Page 7 (GIF))

Some Related Links

• DNA-Inspired Electrostatics. Gelbart, et al. Physics Today 53, no. 38 (2000). (PDF)
• Electrostatics in DNA-peptide Complexes; from a Course on Principles of Protein Structure
• Macromolecular Electrostatistics; from a Course at Modeling Biological Marcomolecules at UCSD
• Ten Years of Tension: Single-molecule DNA Mechanic; Bustamante, et al. Nature 421, no. 423 (2003).
• On Electrostatic Screening; Johm Marko at UIC
• On DNA elasticity; Philip Nelson at UPenn