Cytoskeleton, Organelles, and Tissues

FUnctions of Microtubules

Mitotic Spindlels

Intracellular Transport

Cell movement: Flagella

Kinesins

motor protein that moves cargo on MT filamnets towars th e+ end

Dynein

motor protein that moves cargo on MT filaments toward the - end

Actin Functions

Maintains cell shape

muscle contraction

cell migration

IF Functions

Mechanical Strength

Nucleus Shape

tight junction

type of cell to cell adhesion between apical side nad basal lamina

actin filaments w

CAMs: claudins and occludins

Adherens junction

joins an actin bundle ine one cell to similar bundle in neighborring cell

CAM: cadherins

accessory protein: linker proteins

contraction of actin filaments linked from cell to cell via this junction can acause formation of tubes

Desmosome

joins the IF in one cell to those in a neighbor (mostly keratin)

confers greta tensile stregnth to eptihelial sheets

characteristic of tough exposed epithelia

CAMs: desmosomal cadherins

accessory protein: adapter proteins

Gap junctions

Form channels that allow small intracellular water-soluble molcules inclduing inorganix ions and metabolites to pass from cell to cell

→ electrical signals as well

CAM: Connexin

semidesmosome

anchors IF in the cell to the basal lamina

CAM: cadherins

accessory proteins: integrins

ER

synthesis of most lipidsl syntehsis of proteins for distriubution to many organelles and to the plasma membrane

golgi apparatus

modification, sorting, and packgaing of proteins and lipids for either secretion or delivery to another organelle

Lyosomes

intracellular degradtion

mitochondria

ATP synthesis by oxidative phsophorylation

Endosomes

sorting endocytosed material

myosin-myosin motor protein, capping, side binding, corss linking, severing, nucleating , bundling

functions of actin binding proteins