network of protein fibers extending throughout the cytoplasm function in providing for both...
TRANSCRIPT
Cytoskeleton
Network of protein fibers extending throughout the cytoplasm
Function in providing for both structural support and cell motility Require interaction of the cytoskeleton with
motor proteins Three main kinds of fibers make up the
cytoskeleton:
Microtubules
Hollow rods Composed of globular proteins called
tubulins Functions:
Cellular support Tracks for organelle movement Separation of chromosomes during cell
division Involved in the motility of the cell
Centrosomes and centrioles
Centrosome – region located near the nucleus
Centriole – pair of cylindrical structures located in the centrosome of animal cells Composed of nine sets of triplet microtubules
arranged in a ring May organize microtubule assembly during
cell division
Cilia and flagella
Locomotor organelles formed from a specialized arrangement of microtubules
Unicellular eukaryotic organisms are propelled through water by cilia or flagella
Motile sperm cells (animals, algae, some plants) are flagellated
May function to draw fluid across the surface of stationary cells (ciliated cells lining trachea)
Microfilaments (actin filaments)
Solid rods Composed mainly of proteins called actin Function:
Helps supports the cell’s shape
Participate in muscle contraction
Responsible for localized contraction of cells (dividing animal cell)
Microfilaments function (cont.)
Elongation and contraction of pseudopodia during amoeboid movement
Involved in cytoplasmic streaming found in plant cells
Cytoplasmic streaming (cyclosis) – flowing of the entire cytoplasm around the space between the vacuole and plasma membrane in a plant cell