BIOMG 1350 Lecture Notes - Lecture 5: Skeletal Muscle, Myosin Head, Myosin

• School: Cornell University
• Department: Molecular Biology and Genetics
• Course: BIOMG 1350
• Professor: Huffaker

Document Summary

Molecular motors: different conformational states based on different atp states, move along tracks: microfilaments and microtubules. Microtubules are hollow tubes of tubulin: tubulin heterodimer=microtubule subunit, made up of protofilaments (13 per microtubule) Builds around hollow-like, lumen in the middle. Microtubules grow from organizing center: animal"s mtoc is centrosome, elongate from it. Plus end extends to cell: radial ray. Microtubules transport cargo along nerve cell axons: proteins made in nerve cell body need to go to axon terminal. Cannot be done efficiently by diffusion along: long tracks of microtubules along axon (forward and back/recycling) Cytoplasm squeezed from the squid giant axon reveals the motion of organelles. Motor proteins move along microtubules using their globular heads: two globular heads (commonality), differ in tails. Leading head, lagging head: dyneins (minus end, kinesins (plus end) Different motor proteins transport different cargos: motor domains are similar all bind to microtubules, cargo domains differ because they bind different cargos.