Sensory reset

Factual Questions
1

The recent thread What are smells? reminded me of a question that I’ve had for a while.

Smell and taste are triggered by molecules in the sample binding to receptors in the nose or on the tongue. What is the mechanism by which the sample is unbound and the receptor is reset to recieve the next trigger molecule?

2

Since odor molecules don’t bind covalently, simple diffusion is enough to free up the receptors.
See Wikipedia’s piece on Receptor/Ligand binding affinity.