Tissue Architecture Flashcards
what is the function of the cytoskeleton at the sub cellular level?
organization, tensile strength, chromosome segregation, cell polarity, vesicular movement
what is the function of the cytoskeleton at the cellular level?
cell morphology/shape, motility, cell adhesion, division
what is the function of the cytoskeleton at the tissue level?
muscle contraction
what is the main component of microfilament?
actin 7nm
what is the main component of microtubules?
tubulin 25 nm
what is the main component of intermediate filaments?
lamin/cell specific proteins (8-12 nm)
what type of monomers make up microfilaments? what do they form?
g actin monomers
come together to form f actin (filamentous actin)
why is f actin unstable?
it is constantly undergoing addition (plus end) and removal (minus end) of g actin monomers
it has structural polarity
what is the main functions of microfilaments?
cell movement, locomotion, phagocytosis, cell division, contraction
how does f actin become more stable? (give specific examples)
becomes more stable by joining other proteins
accessory proteins, nucleating proteins, monomoer sequestering proteins, bundling proteins, side binding proteins
how do these proteins work with f actin?
accessory proteins nucleating proteins monomoer sequestering proteins bundling proteins side binding proteins
accessory proteins- stabilize, strengthen, cross link
nucleating proteins- stop monomer removal
monomoer sequestering proteins- semester monomers lol
bundling proteins
side binding proteins- stabilize and bind blocking sites for other proteins
what does phalloidin do?
bind and stabiles microfilaments
(death cap mushroom)
used in microscopy
what does cytochalasin do?
caps microfilaments plus end (no polymerization)
what does latrunculin do?
binds actin monomers and prevents polymerization
what are microtubule subunits and how do they work?
tubulin proteins - made of alpha and beta subunits
form heterodimers
heterodimers come together and form protofilaments
(polarity- heterodimers get added to the plus end of protofilaments )
how many protofilaments make up a microtubule
13
come together around a microtubule core
what is the main function of microtubules?
support shape of cell/organization
- cell organization: make tracks/roads for vesicles to move through
- cell division: interaction with mitotic spindle (extend from centrosome to chromosome)
- part of cilia and flagella in ciliated cells
how do drugs target microtubules in cancer cells?
microtubules targeted –> can’t pull apart chromatin in cell division –> cancer cells cant undergo cell division
how does taxol work?
binds to and stabilizes microtubules
how do colchicine and colcemid work?
binds tubulin dimers/ prevents polymerization