Biophysical Currents bannerCurrent Topics in Biophysics (SC/BPHS 2090 3.0)

Lew Lectures | Jerzak Lectures | Guest Lectures |


course syllabus [in pdf format]

Lew Lectures

GROWTH AND FORM: Allometry [01]fractal tree

  • growth and life cycle
  • dimensional analysis
  • The relations between organismal size, life cycle and physiological function (metabolism, etc.) will be introduced to form a general overview of the physical envelope of organismal life.

    GROWTH AND FORM: Biomechanical Constraints on Growth and Form [02]

  • the height of a jump
  • the height of a tree
  • The relations of force and motion will be explored in the context of 'defying' gravity (to explain why fleas and humans are able to jump to the same height). The height of a tree relates to growing high to optimize light collecting for photosynthesis, the strength of materials and how they limit height, and the need to supply water to the topmost regions of the tree, all constrained by physical limits.

    DIFFUSION, ADVECTION AND BIOLOGICAL PUMPS: The Evolution of Multi-Cellularity [03]

    random walk in three dimensions
  • Diffusion: Thermodynamic and molecular explanations from Einstein
  • Einstein's explanation, a derivation from a two-dimensional random walk, was the starting point for a physical explanation of the diffusive flux of neutral solutes, in solution (Fick's equations).
  • Time Dependence
  • The constraints on biological organisms as a consequence of the slowness of diffusion over long distances will be presented.

    DIFFUSION, ADVECTION AND BIOLOGICAL PUMPS: Advection and the Peclet Number

  • Laminar flow at low Reynolds number
  • Nutrient supply by diffusion or advection
  • As multicellular organisms evolved, their size increased. This creates a challenge: How to supply nutrients at sizes where diffurion is too slow. Advective flow can work, the Peclet number compares the relative contributions of advection and diffusion.
    Volvox is used as a case study of the utility of advective flow for a relatively simple multi-cellular form.
  • Biological pump mechanisms causing advective flow
  • The remarkable diversity of advective pumps in biological organisms is outlined
  • Xylem feeding insects
  • Cicadas and spittlebugs are used as an example of a relatively simple valve-less chamber pump

    MOLECULAR MOTORS: Cellular Movement [04]

  • Reynold's number: Laminar and turbulent flow
  • Viscosity and drag
  • Small sizes, low velocities and viscosity create a very different physical 'universe' for small versus large organisms.

    MOLECULAR MOTORS: Bacterial Motility [05]

  • Rotatory engines
  • Chemiosmotics (energetics)
  • Vectorial movement of hydronium ions passing through the stator/rotor causes rotatory motion of the flagella and thus bacterial motility.

    READINGS for Lew Lectures

    Provided on e-reserves [link] or on the Moodle website [link] for the course.

  • [01]Alexander, R. McNeill (1971) Size and Shape. Edward Arnold (Publishers) Limited. Chapters 1 and 2;
    West, Geoffrey B. and James H. Brown (2004) Life's universal scaling laws. Physics Today (September) pp. 36-42.
  • [02]Thompson, D'Arcy Wentworth (1961) On Growth and Form (ed. By John Tyler Bonner). Cambridge University Press. Pp. 26-28;
    McMahon, Thomas (1973) Size and shape in biology. Science 179:1201-1204;
    Tyree, Melvin T. (2003) Tree hydraulics. Nature 423:923.
  • [03]Einstein, Albert (1907). Investigations on the Theory of the Brownian Movement. Edited by R. Furth. Translated by A.D. Cowper. Published by Dover Publications. Chapter V (The elementary theory of the Brownian motion).
  • [04]Purcell, EM (1977) Life at low Reynolds number. American Journal of Physics 45:3-11.
  • [05]Berg, HC (2000) Motile behavior of bacteria. Physics Today (January) pp. 2-7

  • Jerzak Lectures

    ABSORPTION AND LUMINESCENCE MOLECULAR SPECTROSCOPYwavelet diagram

  • Electromagnetic waves and photons
  • Atomic and molecular orbitals
  • Energy diagrams
  • Absorption and emission of radiation
  • Fluorescence and phosphorescence in biology
  • Energy transfer and charge transfer in biology
  • Photodynamic cancer therapy
  • Photosynthesis
  • NUCLEAR PHYSICS AND BIOLOGY AND MEDICINE

  • Nuclear binding energy
  • Types of radioactive decays
  • The rate of radioactive decay
  • Effects of nuclear radiation on living organisms
  • Radiation dose
  • Radioisotopes in biology and medicine
  • NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY/MAGNETIC RESONANCE IMAGING

  • Spin angular momentum and magnetic dipole moment in magnetic field
  • NMR spectrometer
  • Chemical shift
  • Spin-spin splitting
  • Spin-lattice relaxation time and spin-spin relaxation time
  • MRI in medicine
  • Brain imaging (FMRI)
  • NANOBIOPHYSICSGramicidin ion channel

  • Nanoparticles
  • Magnetic hyperthermia cancer therapy
  • Nanoparticles in radiotheraphy
  • Nanoparticles in image enhancement
  • Nanoparticles in drug delivery
  • READINGS for Jerzak Lectures

    will be provided to students in hardcopy format.
  • UV-VIS Spectroscopy
  • Nuclear biophysics
  • NMR/MRI
  • Laser tweezers
  • Neurobiophysics
  • Nanobiophysics

  • Guest Lectures

  • To Be Announced (when available)