The Biology of Taste and Smell Taste (gustation) and smell (olfaction) are our primary chemical senses, functioning through specialized receptors that detect environmental molecules and translate them into neural signals.

• Taste: Humans detect five basic tastes using taste buds on the tongue: sweet, umami, bitter, salty, and sour. Sweet, umami, and bitter tastes are detected by G-protein-coupled receptors (GPCRs), specifically the TAS1R and TAS2R families. Salty taste is primarily detected via ion channels like ENaC, while the recently discovered OTOP1 proton channel is responsible for sensing sourness. Additionally, Transient Receptor Potential (TRP) channels, like TRPV1, mediate chemesthesis—the perception of pain, heat, and spiciness from compounds like capsaicin.
• Smell: Volatile odorants bind to hundreds of different olfacto ...