cell signalling chat gpt Flashcards
What are the three major classes of cell-surface receptor proteins?
Ion-channel-coupled receptors, G-protein-coupled receptors, and Enzyme-coupled receptors.
What do most extracellular signal molecules do to influence target cells?
They bind to specific receptor proteins on the surface of target cells and do not enter the cytosol or nucleus.
What is the function of cell-surface receptors?
They act as signal transducers by converting an extracellular ligand-binding event into intracellular signals that alter the behavior of the target cell.
What are ion-channel-coupled receptors also known as?
Transmitter-gated ion channels or ionotropic receptors.
What is the primary role of ion-channel-coupled receptors?
To mediate rapid synaptic signaling between nerve cells and other electrically excitable target cells like nerve and muscle cells.
How do ion-channel-coupled receptors function?
They transiently open or close an ion channel, changing the ion permeability of the plasma membrane and the excitability of the postsynaptic target cell.
What mediates the signaling of ion-channel-coupled receptors?
A small number of neurotransmitters.
What do G-protein-coupled receptors do?
They indirectly regulate the activity of a plasma-membrane-bound target protein, such as an enzyme or ion channel.
What mediates the interaction between activated G-protein-coupled receptors and their target proteins?
A trimeric GTP-binding protein (G protein).
What happens when the target protein in G-protein-coupled receptor signaling is an enzyme?
The concentration of one or more small intracellular signaling molecules changes.
What happens when the target protein in G-protein-coupled receptor signaling is an ion channel?
The ion permeability of the plasma membrane changes.
What do small intracellular signaling molecules do in G-protein-coupled receptor pathways?
They alter the behavior of other signaling proteins in the cell.
What do enzyme-coupled receptors do?
They function as enzymes or associate directly with enzymes that they activate.
What is the structure of enzyme-coupled receptors?
They are usually single-pass transmembrane proteins with an extracellular ligand-binding site and an intracellular catalytic or enzyme-binding site.
What types of enzymes are most enzyme-coupled receptors associated with?
Protein kinases, which phosphorylate specific sets of proteins in the target cell when activated.
