Kapitel 17 Flashcards
Thin - flexible protein filament made from a chain of globular actin molecules; a major constituent of all eukaryotic cells - this cytoskeletal element is essential for cell movement and for the contraction of muscle cells.
actin filament
Protein that interacts with actin monomers or filaments to control the assembly - structure - and behavior of actin filaments and networks.
actin-binding protein
Specialized layer of cytoplasm on the inner face of the plasma membrane. In animal cells - it is rich in the actin filaments that govern cell shape and drive cell movement.
cell cortex
Cylindrical array of microtubules usually found in pairs at the center of a centrosome in animal cells. Also found at the base of cilia and flagella - where they are called basal bodies.
centriole
Microtubule-organizing center that sits near the nucleus in an animal cell; during the cell cycle - this structure duplicates to form the two poles of the mitotic spindle.
centrosome
Hairlike structure made of microtubules found on the surface of many eukaryotic cells; when present in large numbers - its rhythmic beating can drive the movement of fluid over the cell surface - as in the epithelium of the lungs.
cilium (plural cilia)
The rapid switching between growth and shrinkage shown by microtubules.
dynamic instability
Motor protein that uses the energy of ATP hydrolysis to move toward the minus end of a microtubule. One form of the protein is responsible for the bending of cilia.
dynein
Long - thin - actin-containing extension on the surface of an animal cell. Sometimes has an exploratory function - as in a growth cone.
filopodium (plural filopodia)
Long - whiplike structure capable of propelling a cell through a fluid medium with its rhythmic beating. Eukaryotic flagella are longer versions of cilia; bacterial flagella are completely different - being smaller and simpler in construction.
flagellum (plural flagella)
Fibrous cytoskeletal element - about 10 nm in diameter - that forms ropelike networks in animal cells; helps cells resist tension applied from outside.
intermediate filament
Class of intermediate filament abundant in epithelial cells - where it provides tensile strength; main structural component of hair - feathers - and claws.
keratin filament
A large family of motor proteins that uses the energy of ATP hydrolysis to move toward the plus end of a microtubule.
kinesin
Dynamic sheetlike extension on the surface of an animal cell - especially one migrating over a surface.
lamellipodium (plural lamellipodia)
Long - stiff - cylindrical structure composed of the protein tubulin. Used by eukaryotic cells to organize their cytoplasm and guide the intracellular transport of macromolecules and organelles.
microtubule
