Taste
Research

The receptors for the basic tastes of bitter, sweet and savory have been identified. They are G protein-coupled receptors. The cells that detect sourness have been identified as a subpopulation that express the protein PKD2L1, and The responses are mediated by an influx of protons into the cells. As of 2019, molecular mechanisms for each taste appear to be different, although all taste perception relies on activation of P2X purinoreceptors on sensory nerves.
detectable_content:number_placeholders[8], combination:two_responses