Biosignalling Flashcards
What are the 4 types of intercellular signalling?
Endocrine, paracrine, neuronal, contact-dependent
What is endocrine signalling?
The signalling molecules from one cell/tissue travel to other cells/tissues via the bloodstream
What is paracrine signalling?
The signalling molecules from one cell act on cells in the immediate surrounding area
What is neuronal signalling?
The signalling molecules are released from the end plate of a neuronal cell and travel across a synapse to the receptors on a target cell
What is contact-dependent signalling?
The signalling molecules are expressed on the cell surface of one cell and bind to the receptors of another cell when the two come into contact
What is the cell response?
The sum of all the signals the cell receives
What do fast cell responses involve?
Involves altering the protein function in the cell (milliseconds - minutes)
What do slow cell responses involve?
Involves altering gene expression (minutes - hours)
Can hydrophilic signalling molecules enter the cell?
No - only hydrophobic ones can
What are the 3 types of cell surface receptors?
Ion-channel-coupled receptors, G-protein-couple receptors (GPCR), enzyme-coupled receptors
Where would you find ion-channel-coupled receptors?
On the surface of electrically excitable cells (i.e. muscle and nerve cells)
Give an example of a GPCR.
Adrenaline binding to the β-adrenergic GCPR in the plasma membrane of skeletal muscle cells to stimulate glycogen breakdown
Give an example of an enzyme-coupled receptor.
Receptor tyrosine kinases e.g. insulin receptors and epidermal growth factor receptors
