Intracellular Communication & Pharmacology Flashcards
Functions of the cell membrane:
- Protective barrier
- Regulates transport in and out the cell or sub cellular domain
- Allows selective receptivity and signal transduction
- Allows cell recognition
- Allows directed cell or organelle motility
- Forms specialised junctions that allow cell adhesion or communication
Who came up with the ‘Fluid Mosaic Model’ 1972?
Singer and Nicolson
Explain the Fluid Mosaic Model
Proposed through microscopy and thermodynamic data:
-proteins must transverse the membrane = non-polar groups would match with non-polar regions and that polar groups would lie near polar regions
- the lipid bilayer gives fluidity and elasticity to the membrane
- small amounts of carbohydrates are also found in the cell membrane (chain of carbohydrates attached to proteins or lipid bilayer)
Protein example of a transporter in the plasma membrane
Na+ pump
Function of the Na+ pump
actively pumps out of cells and K+ in
Protein example of an ion channel
K+ leak channel
Function of K+ leak ion channel
allows K+ ions to leave cells, thereby having a major influence on cell excitability
Protein example of an anchor
Integrins
Function of integrins
link intracellular actin filaments to extracellular matrix proteins
Protein example of a receptor
Platelet-derived growth factor (PDGF) receptor
Function of platelet-derived growth factor
binds extracellular PDGF and as a consequence, generates intracellular signal that cause the cell to grow and divide
Protein example of enzyme
Adenylyl cyclase
Function of adenylyl cyclase
catalyses the production of the small intracellular signalling molecule cyclic AMP in response to extracellular signals
What is selective permeability?
Lipid bilayers are selectively permeable - it allows the movement of certain substances across the membrane
