concept 6.6: the cytoskeleton is a network of fibers that organizes structures and activites in the cell

cytoskelton

a network of fibers extending throughout the cytoplasm that organized the cells structures and activies and achors many organelles

what are the 3 types of molecular structures that compose the cytoskeleton

microtubes (largest)

intermediate filaments

microfilaments (smallest)

what does the cytoskeleton do

supports the cell and helps it maintain its shape

how does the cytoskeleton assist with motility

interacts with motor proteins and allows vesicles to travel along tracks provided by it

microtubes

thickest of the three components of the cytoskeleton

intermediate filaments

middle range diameter filaments

micro filaments/ actin filaments

the thinnest components

functions of microtubules

found in eukarytoic cells and shape the cell, guild movement of organelles, separate chromosomes during cell division

where do microtubules come from

in animal cells they come from the centrosome near the nucleus

what do microtubules control

the beating of flagella and cilia, which are extensions that project from some cells

how are unicellular protists propelled through water with

with cilia or flagella

describe cilia and flagella

use ATP to power them, core of microtubes sheathed by the plasma membrane and a motor proteins called dynein which drives their movement

dynein

has 2 feet that walk along the microtubules powered by ATP and their feet alternately grab, move, and release the outer microtubules and their movement forces the cilia or flaggela to bend

purpose of intermediate filaments

more permanent fixtures and not static or dynamic so they support cell shape and fix organelles in place

function of microfilaments

solid rods that form a 3D network called the cortex that supports the cell’s shape

what proteins to microfilaments need

actin and myosin allow movement

cytoplasmic streaming

a circular flow of cytoplasm within cells driven by actin protein interactions