pt.2 study guide cytoplasm& junctions

cytoskeleton

a network of protein fibers in the cytoplasma

1.) microtubules

structure: hollow tubes made of protein tubulin

functions: maintain cell shape and structures, form spindal fibers that separate chromosomes during cell division, makes up cillia & flagella for movement

2.) Intermediate fibers

structures: rope-like fibers made of proteins

functions: provides strength to cells,

help cells resist tension or stretching

3.) microfilaments

structure: thin, solid, rods made of protein actin

Function: support cells shape, help cells movement, assist in cytokinesia

cell junctions (3 in animal)

connect cells to each other and allow communication between them

1.) tight junction

• seals cells tightly together so nothing leaks

• found in places like the stomach lining or bladder

2.) Desmosomes (anchoring junctions)

• act like a metal that hold cells tg but allow some flexibility

• found in skin and muscle tissue where stretching occur

Gap junctions (communicating junctions)

• small channels that allow ions and molecules to pass b/w cells

• important for communication in heart and nerve cells

plasmodesmata (in plant cells)

• channels that pass through cell walls to connect the cytoplasma of neighboring cells

• allow water, ions, and small molecules to move b/w cells

• functions like gap junctions in animals