Cell Adhesion Flashcards
What are the two types of extracellular matrix?
Basement membrane/basal lamina and fibrillar matrix
Basement membrane contains collagen IV and surrounds epithelial and some non-epithelial cells. Fibrillar matrix is a 3D matrix composed of various fibers, including collagen I and elastin.
What is the function of tight junctions?
Seals off the cells and prevents passage of molecules
Tight junctions turn epithelia into barriers and help maintain water retention.
What is an adherens junction?
Cell-cell anchoring junctions holding cells together
Adherens junctions are linked to the actin cytoskeleton, which helps in cell movement and shape changes.
Define desmosome.
Cell-cell anchoring junction
Desmosomes provide mechanical stability to tissues by linking intermediate filaments.
What is the role of gap junctions?
Channel-forming junction that allows exchange through gaps in plasma membrane
Gap junctions facilitate chemical and electrical coupling between adjacent cells.
What are hemidesmosomes?
Cell-matrix anchoring junction
Hemidesmosomes are much smaller than desmosomes and anchor epithelial cells to the basement membrane.
What do intermediate filaments provide for cells?
Stability against mechanical stress
Mutations in intermediate filaments may lead to cell rupture and damage to skin integrity.
What is the function of focal adhesions?
Link the actin cytoskeleton to the extracellular matrix via integrins
Focal adhesions form as cells expand and reach out across surfaces due to actin-myosin interactions.
What are cadherins?
Ca2+ dependent adhesion molecules
Cadherins allow cells to cluster and find each other, playing a critical role in tissue formation.
Fill in the blank: _______ are linked to the actin cytoskeleton and mediate contracting forces.
Adherens junctions
True or False: Tight junctions allow passage of small molecules.
False
What is the role of calcium in the extracellular matrix?
Necessary for morphogenesis and proper functioning of junctions
Calcium plays a crucial role in the activity of cadherins and adherens junctions.
What type of matrix is described as having sparse cells buried within it?
Fibrillar matrix
What type of junction is characterized by forming pores?
Gap junction
Fill in the blank: _______ junctions surround the apical surface of epithelial cells.
Tight
