BICD 110 Lecture Notes - Lecture 11: Gtpase, Paclitaxel, Hydrolysis
28 Jun 2018
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BICD110 Lecture 11 Notes 5/10/18
- 3 cytoskeletal systems are made up of different proteins that form filaments or polymers
microfilaments (5-9 nm) microtubules (25 nm) intermediate filaments (10 nm)
actin binds ATP alpha/beta-tubulin bind GTP don’t bind nucleotide
form rigid gels, networks,
and linear bundles
rigid and not easily bent great tensile strength
regulated assembly from
a large number of
locations in same cell
regulated assembly from
small number of locations (if
cell contains cilia/flagella,
more locations regulated)
assembled onto pre-existing
filaments
highly dynamic highly dynamic less dynamic
polarized polarized unpolarized
tracks for myosins tracks for kinesins and
dyneins
no motors
used for contractile
machinery and network
at cell cortex
used for organization and
long-range transport of
organelles
used for cell and tissue integrity
- microtubules
oin every cell, there’s a microtubule organizing center (MTOC). It’s almost always next to
the nucleus. Called the centrosome during interphase
ofunctions of microtubules for all cells
1) highways for membrane-bound organelles and secretory vesicles to move on
transport in a neuron: long line of staggered microtubules
in neuron allows pathway to end of neuron. Protein
synthesis occurs in cell body; with motors, allows much
faster movement compared to diffusion (8 years), to move
things that are needed at the synaptic terminal. MTOC
found in cell body
2) help form the ER network
3) mitotic spindle: along which chromosomes move at mitosis
MTOC is the centrosome (spindle poles). Microtubules form
out of 2 MTOCs. Motors on chromosomes and microtubules
cause microtubules to shorten, allowing chromosomes to
move to opposite poles
ofunctions in specialized cells
4) cilia: movement of objects over the cell (ciliated epithelium)
cilia on ciliated epithelium move particles over cells
base of cilia contains basal body (same as MTOC), allowing
microtubules to form
throat contains 109 cilia/cm2
oviduct: cilia sweep egg along oviduct to go to right place
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Bicd110 lecture 11 notes 5/10/18 microfilaments (5-9 nm) Microtubules: in every cell, there"s a microtubule organizing center (mtoc). Called the centrosome during interphase: functions of microtubules for all cells, highways for membrane-bound organelles and secretory vesicles to move on transport in a neuron: long line of staggered microtubules in neuron allows pathway to end of neuron. Protein synthesis occurs in cell body; with motors, allows much faster movement compared to diffusion (8 years), to move things that are needed at the synaptic terminal. Mtoc found in cell body: help form the er network, mitotic spindle: along which chromosomes move at mitosis. Organize the placement of the golgi; the golgi is almost always located next to the centrosome. Microtubule: polymerization and depolymerization: structure of microtubules. Made of tubulin dimers: alpha and beta. 13 protofilaments join together to form microtubules (-) end attached to centrosome, dimers added to (+) end.
