Modification of Plasma Membrane
In this article we will discuss about:- Microvilli, Inter digitations, Tight junction, Gap junction, Desmosomes and Plasmodesmata
What is Modification of Plasma Membrane?
- Plasma membrane shows some specialized structures
- To perform some additional functions plasma membrane shows some changes
- Free Surface Modification
- Junctional Complex
[ Must Read: Fluid Mosaic Model of Plasma Membrane ]
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Free Surface Modification
Microvilli
- Minute finger like projections arising from surface of certain cells
- Single cell contains more than 3000 microvilli
- Found in epithelial cells of intestine, kidney tubules, gall bladder and hepatic cells
- Function: increase the surface area for absorption
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Junctional Complex
Inter digitations
- Plasma membrane of adjacent cells project into cytoplasm as finger-like projections
- Found in lymph nodes and lymphoid tissues
- Function: increase surface area for exchange of substance between the cells
Tight junction
- Plasma membrane of adjacent cells fuses by extrinsic proteins
- Found in brain cells, gall bladder and intestinal cells
- Function: adhesion
Gap junction
- Gap junction is channel through two cell membranes across the intercellular space between two adjacent cells
- Found in cardiac muscles
- Function: conduct electrical signals & passage of ions, sugar, vitamin and metabolites
Desmosomes
- Desmosomes are thickened areas of plasma membrane of two adjacent cells
- Found in cardiac muscle and skin cells
- Function: help to glue the cells together
Plasmodesmata
- Cytoplasm of adjacent cell connected with cytoplasmic strands
- Found in plant cells
- Function: exchange of materials between two cells
