Answer
The energy transduction takes place in the olfactory receptor protein.
Work Step by Step
The olfactory epithelium has basal (stem) cells, supporting (insulating) cells, and olfactory receptor cells.
The olfactory receptor cells are bipolar first order neurons of the olfactory pathway. In the dendrite pole the receptor cells bear several non-motile cilia. Within the plasma membrane of these cila are receptor proteins of the G family When an odorant( chemical ligand) binds to a G receptor protein , the G-protein activates the enzyme adenyl cyclase and the second messenger cAMP is produced. Cyclic AMP opens sodium channels in the receptor proteins and N+ ions stream into the cytosol. The influx of positive sodium ions depolarizes the receptor cell to varying degrees and a generator potential develops. If the depolarization reaches threshold, an action potential (AP) is initiated which travels ( towards the olfactory bulb) along the axon of the olfactory receptor cell.
