How do G-protein coupled receptors work to transmit signals within cells?

G-protein coupled receptors (GPCRs) work by binding to specific molecules outside the cell, which triggers a series of events inside the cell. When a molecule binds to the GPCR, it activates a G-protein inside the cell, which then triggers a cascade of signaling pathways that ultimately lead to a cellular response. This allows cells to respond to external signals and regulate various processes within the body.