Question

Construct a table that illustrates the structure and function of the glycocalyx, ECM, 3 types of cytoskeletal elements, and the 3 types of cell-cell junctions. In the table include the specific macromolecules that make up these structures, specific properties these structures give to the cell or tissue. Give one example of a tissue or cell whose properties depend on each of these structures.

Answer 1

	structure	Composition	Function	Location
Glcocalyx	fibrous meshwork of carbohydrates	glycoprotein and glycolipid chained polysaccharide	in bacteria it provide protection and promote the adhesion endothelial glycocalyx regulates the vascular permeability modulate the interactions between blood and endothelial cells	capsule of bacteria present in endothelial cells
ECM	network of fibrous proteins and proteoglycans that fills the space between the cells	water fibrous proteins (collagens, elastins, laminins) proteoglycans.	provide tissues strength and support regulate intercellular communication structural integrity.	present in extracellular space
Cytoskeletal elements microtubules	Hollow tube Diameter: 24-25	tubulin	Motility of eukaryote Maintain cell shape Movement of intracellular materials	Cilia and flagella
actin filaments (microfilaments)	solid Diameter: 5-9	actin	Muscle contraction cell shape change cytokinesis	muscle
intermediate filaments	Hollow tube Diameter: 10	number of different subunit proteins	Integrate contractile unit in muscle Structural function of cytoskeleton	cytoskeletal component
Cell Junctions Desmosomes and hemidesmosomes (anchoring junctions)	keeping the cells together structural cohesion of tissues.	Desmosomes: Cadherin hemidesmosomes; Integrins	Desmosomes: link cell to another cell. hemidesmosomes;  link cell to the extracellular matrix.	found in tissues that are prone to constant mechanical stress, e.g. skin and heart.
Tight junctions (occluding junctions)	Epithelial cells with tight junctions may be described as tight or leaky depending on the presence	occludin claudin	maintain the polarity of cells and the osmotic balance cell adhesion permeability of paracellular barrier	blood-brain barrier
Gap junctions (communicating junction)	intercellular connection	connexins.	allowing the direct passage of ions, small molecules, or electrical impulses from one cell to another	ardiac muscle tissues, gap junctions form a part of the intercalated disc