1.4c - Hydrophilic Signals and Transduction Flashcards
Hydrophilic signalling molecules bind to…
transmembrane receptors and do not enter the cytosol
2 examples of hydrophilic extracellular signalling molecules
peptide hormones and neurotransmitters
Transmembrane receptors change conformation when…
the ligand binds to the extracellular face
When the ligand binds to the extracellular face the signal molecule…
does not enter the cell but the signal is transduced across the plasma membrane
Transmembrane receptors act as…
signal inducers by converting the extracellular ligand-binding event into intracellular signals, which alter the behaviour of the cell
Transduced hydrophilic signals often involve…
G-proteins or cascades of phosphorylation by kinase enzymes
Activated receptors are…
receptors that have bound a signalling molecule
G-proteins relay signals from…
activated receptors to target proteins such as enzymes and ion channels
Phosphorylation cascades allow…
more than one intracellular signalling pathway to be activated
Phosphorylation cascades involve a…
series of events with one kinase activating the next in the sequence and so on
Phosphorylation cascades can result in…
the phosphorylation of many proteins as a result of the original signalling event
Binding of the peptide hormone insulin to its receptor results in…
an intracellular signalling cascade that triggers the recruitment of GLUT4 glucose transporter proteins to the cell membrane of fat and muscle cells
Binding of insulin to its receptor causes…
a conformational change that triggers phosphorylation of the receptor
The phosphorylation of the receptor starts a phosphorylation cascade inside the cell, which eventually leads to…
GLUT4-containing vesicles being transported to the cell membrane
Diabetes mellitus can be caused by…
failure to produce insulin (type 1) or loss of receptor function (type 2)
