Fourth Year

Introduction to Biophysics: Introduction to a new world, A physicist’s approach to Biophysics. Water: Introduction, Structure (molecular structure, liquid and solid), unusual physical properties, Bulk vs. local structures, Diffusion and chemical reactions in water, solute and the solvent power of water. Structures (from 0.1 - 10 nm and larger): Software to display and analyze biological structures, Solvents, Small molecules, Medium-sized molecules (Components of large biomolecules), Forces and free energies, Biopolymers, Macromolecules. Biomolecules &biomolecular assemblies: Measuring properties of 3-D aggregates, small aggregates, large aggregates, 2-D aggregates (membranes). Putting a cell together (physical sketch): Minimal, prokaryotic, and eukaryotic cells, physiology (selective overview); reproduction, DNA, and the cell nucleus, sensors and recognition, responding to the outside world without eyes. Electrical and Magnetic Properties of cells: Electrical properties of body tissue (electrical conduction through blood and tissue), Nerve conduction (Cell membrane and Ion distributions, types of cell membrane excitations, model of electrical conduction along an axon), Ion channels, hair cells, balance, taste and smell; Electrical properties of the heart; Electrical signals in the brain; Effects of electric shock, Magnetic properties (magnetic field from an axon, magnetic sense), Electromagnetic waves. Light and life: Light (our energy source), Crucial differences between one 5 eV and 2.5 eV photons, Properties of photons, Scattering and reflection, Absorption spectra, Emission spectra; Einstein relations between absorption and emission of atoms, Intersystem crossing: singlets (S = 0) to triplets (S =1), Energy transfer (FRET). Mechanics and Dynamics: Conservation laws, Newton’s laws, forces and torques, Friction, Gravitational forces, Volume changes and compressibility, Stress and strain; Dissipation, Inertia, Disorder, Fluids and turbulence. Diffusion & polymer conformation: Review of kinetic theory of gases (Implications for biomolecular averaging), 1-D random walk (probabilities and distributions), Spreadsheet model for a 1-D random walk, 3-D random walk, Diffusion in the bulk, reprise of photosynthetic light harvesting, biopolymers—random reprise.