Lecture 16: General principles of cell signalling Flashcards
What are the three roles cell communication is needed for?
Development
Tissue repair
Homeostasis
What are the two general categories of signals?
Signals generated by cell to cell contact
Signals generated by free diffusion of ligands
What are the characteristics of signalling by cell to cell contact?
No release of secreted molecules
Cells make direct contact
Signals in plasma membrane
What is signalling by free diffusion of ligands that can cross the plasma membrane?
Hydrophobic small molecules
Diffuse across plasma membrane and bind receptors in cell
What is signalling by free diffusion of ligands that can’t cross plasma membrane?
Big or hydrophilic
Bind receptors on cell surface
Receptors pass information inside
What is local paracrine signalling?
Mostly within one tissue
Diffusion of signals over short distance
What is local neuronal signalling?
Neurotransmitters act as signal
Local between two cells in synaptic cleft
What is remote endocrine signalling?
Endocrine cells make hormones
Act over whole body via blood stream
What are the three major families of receptors?
Ion channel coupled
G protein coupled
Enzyme coupled
What is the response of ion channel coupled receptors?
Open or close
What is the response of G protein coupled receptors?
Activate G protein
What is the response of enzyme coupled receptors
Activate catalytic activity of intrinsic or associated enzyme
