PH 360 Biophysics, August 2025

Venue: Lecture Hall 4 ( Room F0-11), Department of Physics

Time: Tuesdays & Thursdays 2-3.30

This page will serve as a resource for the PH 360 course at the Department of Physics, IISc. Course content will be updated periodically.

This course will be taught using lecture notes prepared by Sumantra Sarkar. The lecture notes are free to use for non-commercial purposes.

Syllabus: Syllabus-Aug2025

Class team: PH 360: Aug-Dec 2025

Additionally, the suggested readings for this course are the following textbooks.

  1. Physical Biology of the Cell (PBoC), Phillips et.al. Garland Science, 2nd edition.
  2. Biological Physics (BPN), Nelson, Student Edition, Chiliagon Press.
  3. An Introduction to Systems Biology, Alon, 2nd edition, CRC Press.
Class IDClass dateTopicDetailsResources
105-08-2025Introduction 1. What is biophysics?
2. How do we model biological phenomena?
3. Biological units.
4. Estimation techniques.
Lecture Note
207-08-2025Introduction to biophysical models1. Estimating 30 s
2. Rules of estimation
3. Image analysis of E.coli growth
4. Estimating E.coli doubling rate using Bionumbers
5. Resource allocation during cell division
Lecture Note + E. coli growth images + Codes
319-08-2025Thermal equilibrium in cells1. Body temperature
2. Laws of thermodynamics
3. Entropy
4. Maximum entropy distributions
5. Applications
Lecture note

PBoC Ch 5.3, 5.4, 5.5, 5.5.1
421-08-2025Ligand-receptor binding1. Boltzmann distribution
2. Two-state systems
3. Ligand-receptor binding
4. DNA-protein binding
Lecture Note
526-08-2025Cooperative binding1. Regulation of gene expression
2. Gibbs ensemble
3. Ligand-receptor binding revisited
4. Cooperative binding of oxygen to hemoglobin
Lecture Note
628-08-2025Chemical kinetics1. The law of mass action
2. Well-mixed mass action kinetics
3. Rate equations
4. Michaelis-Menten kinetics
5. Population growth kinetics
Lecture Note + Code
702-09-2025Negative autoregulation1. What is systems biology?
2. Response time
3. Network motifs
4. Autoregulation as a network motif
5. Rapid response through auto regulation
Lecture Note
804-09-2025Positive autoregulation + Feedforward loop1. Positive autoregulation
2. Delayed response
3. Bistability
4. FFLs
Lecture Note
909-09-2025Feedforward Loop + Toggle switch1. C1-FFL
2. Logic gates
3. I1-FFL
4. Toggle switch
5. Nullcline analysis
Lecture Note
1011-09-2025Stochastic Chemical Kinetics1. Markov processes
2. Markov state models
3. Master equation
4. Chemical master equation
5. Doob-Gillespie algorithm
Lecture Note + Python Notebooks
1116-09-2025Brownian motion and diffusion1. Random walk
2. Brownian motion
3. Derivation of the diffusion equation from the master equation.
4. Derivation of the Smoluchowski equation.
Lecture Note
1218-09-2025Molecular transport in biological systems1. How do we measure diffusion coefficients?
2. Anomalous diffusion.
3. Non-diffusive transports
Lecture Note
1323-09-2025Guest lecture + Chemotaxis1. Lecture on Phototaxis of Chlamydomonas phototaxis by Prof. Prerna Sharma

2. Discussion of the physics of chemoreception by Berg and Purcell
Lecture Materials
1425-09-2025Mid-term exam
1507-10-2025Polymers as random walks1. Freely-jointed chain model of polymers.
2. Kuhn length
3. Radius of gyration.
4. The concept of persistence length.
Lecture Note
1609-10-2025Beam theory-11. Polymers and cytoskeletal filaments as slender rods.
2. Beams, ribbons, and membranes
3. Bending rigidity of a beam.
4. Persistence length as a measure of bending rigidity
Lecture Note
1714-10-2025Beam theory-2 + Basics of lipid self-assembly1. Buckling of beams under stress.
2. Lipids as ampiphiles
3. Nomenclature of lipids
4. Thermodynamics of equilibrium self-assembly
Lecture materials
1816-10-2025Guest lecture1. Liquid-liquid phase separation by Prof. Shibananda Das
2. Partial differential equations by Soumyadeep Mondal
1921-10-2025Basics of membrane mechanics1. Geometric criteria for lipid assemblies.
2. Cell membranes as an self-assembled structure of lipids.
3. Membrane deformation and associated free energies.
4. Bending of membranes and height fields.
Lecture note
2023-10-2025Molecular motors1. What are molecular motors?
2. Functions of molecular motors.
3. Simple theory of molecular motors.
Lecture materials
2128-10-2025Salty solutions1. Ionic equilibrium
2. DNA condensation in bacteriophage
3. Salty solution
4. Debye-Huckel theory
5. DNA packaging revisited
Lecture note
2230-10-2025Ion channels1. Osmosis
2. Nernst equation
3. Ligand-gated ion channels
4. Allostery
Lecture note
2304-11-2025Biological electricity - I1. Membrane as an electrical circuit
2. Membrane potential
3. Ion channel conductivity
4. Patch-clamp experiments
5. Voltage-gated ion channels
Lecture note
2406-11-2025Biological electricity - II1. Neuron as a cable
2. Cable theory
3. Propagation of depolarization waves
4. Pattern formation
Lecture materials