Biology 224- Chapter 10.2 Liberty University (Dr. Brophy)
Terms in this set (46)
Cells produce an __________________________ for strength and support.
___________________________ use cell junctions to hold adjacent cells together.
Most cell junctions are composed of _________________, and play a variety of roles in cells.
___________________________ Junctions depend on Integral Proteins passing through the cell membrane of the ____________________ of adjacent cells.
During cell junctions, what are the names of the two such proteins?
Cadherins and Integrins
fibrous proteins connected to actin microfilaments in the cytoplasm.
Cadherins extend into the extracellular matrix where _________________ions help them bind to each other.
______________________ are composed of two subunits (blue) that bind other proteins (pink) which then bind to actin microfilaments in the cytoplasm.
In the extracellular matrix, integrin binds to ____________________which then binds to elements of the matrix such as collagen fibers.
___________________________ Junctions form seals between cells.
What are the functions of Tight Junctions?
-Limit movement of materials through intercellular spaces.
- Limit movement of Proteins within the Membrane.
What is the structure of Gap Junctions?
Connexon Proteins form channels connecting the cytoplasm of two adjacent cells.
What is the function of Gap Junctions?
allow passage of ions and small molecules for communication between cells.
In animals, three types of junctions are found between cells:
- anchoring junctions
What is the definition of Anchoring Junctions?
play a role in anchoring cells to each other or to the ECM.
What is the definition of tight junctions?
seal cells together to prevent small molecules from leaking across a layer of cells.
What is the function of gap junctions?
allow cells to communicate directly with each other
Plant cells are connected to each other by a component called the __________________, which cements their cell walls together.
passageways between the cell walls of adjacent cells that can be opened or closed. When opened, they permit the direct diffusion of ions and molecules between the cytosol of cells.
What are the types of cell junctions in plants?
What is Middle lamella?
A polysaccharide layer that cements together the cell walls of adjacent cells.
The invention of what allowed researchers to explore the types of junctions that occur between cells and within the ECM?
Who conducted several studies showing that various types of cellular junctions connect cells to each other?
Marilyn Farquhar and George Palade
What junction is a part of the layer of cells that line the small intestine?
What keeps intestinal cells tightly adhered to one another, forming a strong barrier between the lumen of the intestine and the blood?
A key component of anchoring junctions that form the actual connections are integral membrane proteins called __________________________________.
call adhesion molecules (CAMs)
What are the two types of CAMs?
___________________ and ____________________junctions connect cells to each other via cadherins.
In the _______________, adherens junctions bind to cytoskeletal filaments called ___________ filaments.
Desmosomes are connected to cytoskeletal filaments called _______________________ filaments.
___________________________ connect cells to the extracellular matrix via integrins.
______________ connect cells to the ECM via integrins.
In the cytosol, focal adhesions bind to _________________ filaments.
_______________________ are CAMs that create cell-to-cell junctions.
On the interior of the cell, ___________________ proteins connect cadherins to actin or intermediate filaments of the cytoskeleton.
The __________________of vertebrates and invertebrates contain multiple cadherin genes, which encode slightly different cadherin proteins.
Dimer formation follows a _______________________, or like-to-like, binding mechanism.
What are two types of cadherins?
E-cadherin and N-cadherin
E- cadherin in one cell does not bind to N-cadherin in an adjacent cell to form a ___________________.
N-cadherin binds to N-cadherin but not to E-cadherin in an _________________________.
a group of cell-surface receptor proteins, are a second type of CAM, one that creates connections between cells and the ECM.
Integrins do not require Ca 2+ to function.
________________are critical for keeping cells in their correct locations.
forms a tight seal between adjacent cells, thereby preventing material from leaking between cells.
What are tight junctions made by?
Membrane proteins called occludin and claudin that form interlaced strands in the plasma membrane.
Tight junctions do not have have strong connections with the cytoskeleton.