BIOL 201 Lecture Notes - Lecture 24: Keith R. Porter, Microtubule, Centrosome
27 Nov 2015
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Document Summary
Discovered microtubules in plant cells and then later, all eukaryotes. Saw thin tubular structures made up of 13 protofilaments. Microtubules are found in all eukaryotes: prominent in neurons as well, also found in cilia. Microtubules in animal cells are organized by the centrosome: they tend to radiate out of the centrosome. Microtubules are continuously built, broken down, and rebuilt: even when a cell is standing still, its microtubules are being built. In neurons, they are densely packed in an almost crystalline density: they are the roadways for the transport of protein products produced in the cell body. The rate constants of microtubule polymerization are less clear. When gtp hydrolysis occurs, the dimer wants to curve. Energy stored in the form of strain is released to do work. Transition of state of growth to state of rapid shrinkage is known as a catastrophe
