WEEK 11: RECEPTOR TYPES

Ion Channel Receptors

Receptor proteins part of an ion channel complex that opens or closes in response to ligand binding.

Polarisation of nerve membranes

Change in membrane potential, making the inside of the cell negatively charged compared to the outside.

Induced fit

The changes in a receptor's shape when a messenger binds, facilitating its function.

Nicotinic receptor structure

Composed of 5 subunits made up of 4 different types, with binding occurring mostly on the alpha subunits.

G-protein coupled receptors

Receptors that bind a messenger, leading to activation of G-proteins which trigger further cellular responses.

Ligands

Molecules or ions that bind to other molecules or proteins to form a complex.

Tyrosine Kinase Linked Receptors

Receptors that function as both receptor and enzyme, activated by hormones.

Epidermal Growth Factor Receptor (EGF-R)

A receptor that dimerises and activates signal proteins through phosphorylation.

Intracellular receptors

Receptors that require hydrophobic messengers to cross the cell membrane, often leading to gene transcription.

Desensitization of receptors

The process where receptors decrease in sensitivity due to prolonged exposure to agonists.

Signal transduction via G-proteins

The process of transmitting signals from receptors to target effectors, often involving Gs, Gi, and Gq proteins.

Phosphorylation reactions

Reactions involving the addition of phosphate groups that alter enzyme activity.

Sensitization of receptors

The process where receptors increase in sensitivity due to prolonged exposure to antagonists.

Secondary effect in ion flow

The ion flow across the cell membrane caused by messenger binding, leading to further changes in cell chemistry.