by: marc werner and ashley graydon. cytoskeleton functions keeps organelles in anchored locations ...
TRANSCRIPT
BY: MARC WERNER AND
ASHLEY GRAYDON
CYTOSKELETON FUNCTIONSKeeps organelles in anchored locationsEstablishes and supports the shape of the cellHelps transport materials within the cellAn arrangement of protein fibers found in all
eukaryotic cellsSeparates the chromosomes in mitosis and
meiosis
CYTOSKELETON FIBERSMicrotubules: Organizes the cell and moves
materials within the cellActin Filaments: Accountable for cellular
compressionIntermediate Filaments: Stabilizes the
framework of the cell
MICROTUBULESBuilt by the monomers of alpha and beta
tubulinFound in both animal and plant cellsStraight, hollow cylinder walls made up of 13
protofilamentsGrow at the end of each polymerized dimer There are two types of microtubule motors:
-Kinesins- move toward the positive end of the microtubule
-Dyneins- move toward the negative end of the microtubule
ACTIN FILAMENTSProtein Actin monomers polymerize to form
long thin fibersSmallest of the cytoskeletal filamentsProvides mechanical strength to the cellAnchors the centrosomes at opposite poles of the
cell during mitosisLinks transmembrane proteins to cytoplasmic
proteins (ex cell surface receptors)interact with myosin filaments in skeletal muscle
fibers to provide the force of muscular contraction
INTERMEDIATE FILAMENTSAre cytoplasmic fibersHave several types of intermediate filament:
-Keratins- found in the epithelial cells and also form hair and nails
-Lamins- form a lattice that stabilizes the inner membrane of the nuclear envelope
-Nuerofilaments- strengthen the long axons of neurons
-Vimentins- provide mechanical strength to the muscle and other cells
DISEASES CAUSED BY DEFECTIVE CYTOSKELETONS
Sickle Cell Aneamia- produces defective hemoglobin which alters the red blood cells into the shape of a sickle, the lattice locks into the shape of a sickle, which obstructs the microcirculation
Duchenne Muscular Dystrophy- Mutation in the dystophin gene disrupts the ability of the proteins to hold on to the cytoskeletal elements to the surface of the membrane