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Lecture
Material and Notes
Week 1, Lecture 2: Engineering
in muscle biology and vice versa
Martin Kushmerick
Lecture theme and outline:
- Motility is a hallmark of
life and occurs at various scales of structure.
- Basic mechanism is at the
molecular level - nanotechnology evolved by nature uses a few types
of protein machines to produce mechanical action.
- These motors are organized
into a remarkably ordered array in the case of muscle.
- These are all chemical machines
- chemical free energy drives the processes and continued function depends
on continuous energy supply.
- All muscles and all molecular
motors can only move one way - shortening only.
- Three major properties characterize
muscular action:
- The force-length relationship:
the maximal force obtained is a function of the device length at the
nanoscale of molecules as well as at the macroscopic scale.
- The force velocity relationship:
force depends on the velocity at which the muscle moves.
- The energy used depends
on the biomechanical conditions at all levels. Molecular motors use
one unit of chemical energy per action cycle.
- Engineering needs muscle
biology precisely because the structural and functional relationships
are so elegant and complex; so far there is no human-made machine of
anything like the remarkable "machina carnis."
- Muscle biology needs engineering
because progress depends on quantitative analyses, mathematical modeling
and system integration.
Suggested reading: see
Lecture 1.
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