Chapter 10
This forms a seal that prevents the movement of substances between cells, for instance from the intestinal lumen into the blood.
tight junctions
collagen structure
triple helix shape
Major component of certain parts of plants
woody parts
Adhesive proteins (function)
Adhere ECM components together and to the cell surface
Cell junctions
Adhere cells to each other and to the ECM
Secondary cell wall
After plant cell matures layers
Anchoring junctions
Attach cells to each other and to the ECM Rely on cell adhesion molecules (CAM
Major component of certain parts of animals
Bone and cartilage
Cadherins
Ca2+ dependent adhering molecule create cell-to-cell junctions
Structural protiens
Collagen and Elastin
Gap junctions
Connexon allows passage of ions and small molecules
Integrins
Creates connections between cells and ECM
Plasmodesmata
Different in that they are open channels where the cell membrane of one cell is continuous with adjacent cell membrane Allow passage of ions and molecules between adjacent cells
True-False: Wrinkling observed with aging is do to low production of the extracellular matrix molecule, fibronectin.
False, collagen
Adhesive proteins (types)
Fibronectin and laminin
GAGs have
Highly negatively charge attracts positive ions and water
Tight junctions
Made by occludin and claudin Bind to each to form tight seal Not mechanically strong, not bound to cytoskeleton
Extracellular matrix (ECM)
Network of material secreted from the cells forming a complex meshwork outside of cells
Middle lamella
Plants use additional component of ECM to form cell-to-cell connections pectin
animal ECM is made of
Portions and Polysaccharides
Primary cell wall
between new cells Flexible cellulose
Adherins junctions
cadherins and actin microfiliments
Desmosomes
cadherins to intermediate filaments
Chondroitin sulfate
cartiliage
This polysaccharide is an important ECM component for the exoskeleton of many insects and shellfish.
chitin
Which of the following ECM molecules provides tensile strength?
collagen
Hyaluronic acid
found in skin, eyes, joint fluid
most common Polysaccharides in animal ECM
glycosaminoglycans (GAGs)
Focal adhesions
integrins, ECM to actin microfiliments
Hemidesmosomes
integrins, ECM to intermediate filiments
Gap junctions are to animal cells as ________ are to plant cells?
plasmodesmata
The major macromolecules of the ECM are polysaccharides and
proteins.
Collagen
provides tensile strength Main protein found in bone, cartilage, tendon, skin
Protective cell wall outside the plasma membrane
rigid shape direction
Animal cells secrete ECM that helps
support and organize cells
