Download Notes: Intercellular Junctions

Notes: Intercellular Junctions
Main Concept: How cells interact, communicate, and connect with eachother. Plants have
plasmodesmata that pass through adjoining cell walls. Animal cells have tight junctions,
desmonsomes, and gap junctions.
Vocab:
Plasmodesmata: channels in which plant cell walls are perforated with
Tight Junctions: membranes of neighboring cells are tightly pressed against each
other, bound by specific proteins. Prevent leakage of estracellular fluid across
epithelial cells.
Desmonsomes: (aka. Anchoring junctions) function like rivets, fastening cells
together into strong sheets. Filaments made of study keratin proteins anchor them
in cytoplasm.
Gap Junctions: (aka. Communicating junctions) provide cytoplasmic channels
from one cell to the next. Special membrane proteinsthat surround a pore through
which ions, sugars, a. acids, etc. pass. Necessary for communication b/w cells.
Plants:
Functions of plasmadoesmata: allow cytosol to pass through, which connects
cells, to unify plant inot one living thing, water and small solutes pass from cell to
cell, macromolecules pass through and are transported on cytoskeleton.
Functions of plasma membranes: line the channel of each plamodesma and thus
are continuous.
Animals:
Tight Junctions, desmonsomes, and gap junctions.
All 3 types are common in epithelial tissue which lines the external and internal
surfaces of the body.