Science of Mind

1
Science of Mind

• Single Molecule Biophysics
• Dominique S. Blair
• It requires a very unusual mind to undertake the
  analysis of the obvious. Alfred North Whitehead

2
What is Biophysics?

• Biophysics is that branch of knowledge that
  applies the principles of physics and chemistry
  and the methods of mathematical analysis and
  computer modeling to understand how biological
  systems work.
• Biophysics is a molecular science. It seeks to
  explain biological function in terms of the
  molecular structures and properties of specific
  molecules. These molecules, the sole building
  blocks of living organisms, assemble into cells,
  tissues, and whole organisms by forming complex
  individual structures with dimensions of 10, 100,
  1000, 10,000 nm and larger.

3

• Biophysics is a diverse and eclectic field
  divided into three topic areas
• Molecular Structures Explains the biological
  functions of cells, tissues, and organisms in
  terms of the structure and behavior of biological
  molecules. 
• Biophysical Techniques The characterization of
  molecular structure, the measurement of molecular
  properties, and the observation of molecular
  behavior presents an enormous challenge for
  biological scientists.
• Biophysical Mechanisms Much of the scientific
  success of biophysics depends upon its ability to
  develop detailed physical mechanisms to explain
  specific biological processes.

4
Molecular Structures

• Proteins
• Nucleic Acids
• Carbohydrates
• Lipids Membranes
• Macromolecular Complexes
• Metabolic Pathways
• Molecular Behavior

5
Biophysical Techniques

• Electrophysiology
• Hydrodynamics 
• Microscopy Imaging
• Modeling Simulation
• Single Molecule Techniques
• Spectroscopy

6
Biophysical Mechanisms

• Biomedicine
• Electrical Behavior of Cells
• Energy Transduction in Membranes
• Protein Function
• Membrane Behavior
• Muscle Contraction and Cell Motility
• Protein Folding
• Sensation

7
History of Biophysics

• Bernard Katz, discovered how synapse work
• Alan Hodgkin Andrew Huxley, mathematical theory
  of how ion fluxes produce nerve impulse

• Hermann von Helmholtz, first to measure the
  velocity of nerve impulse studied hearing and
  vision
• Adolf E. Fick who in 1856 published what is
  probably the first biophysics text, Die
  medizinische Physik (Medical Physics).

8
Historycont

• Relationship btw Electricity and Biology
• Sir Isaac Newton in the Principia (1687) wrote of
  a certain most subtle spirit which pervades and
  lies hid in all gross bodies, and that all
  sensation is excited, and the members of animal
  bodies move at the command of the will, namely,
  by the vibrations of this spirit, mutually
  propagated along the solid filaments of the
  nerves, from the outward organs of sense to the
  brain, and from the brain into the muscles.
• Alan Hodgkin and Andrew Huxley, showed how the
  flow of sodium and potassium across the membranes
  of nerves can be coupled to produce the action
  potential, a brief electrical event that
  initiates the action potential, which propagates
  the nervous signal.

9
Hodgkin-Huxley Model
10
Neuron

11
Computational Biophysics

• Understanding the structure and dynamics of
  molecular systems
• High-performance computing to investigate
  molecular dynamics

12
Essence of Scientific Investigation

• Science proceeds by endless and ever
  refining cycles of conjecture (opinion) and
  refutation (disproof) therefore be speculative
  and imaginative in the creation of hypotheses,
  and then challenge them with the utmost rigor,
  using existing knowledge and by mounting the most
  penetrating experimental attacks
• John Eccles