Biology Discussion: Umami Taste


Campbell Biology

Source: Urry, Lisa A.. Campbell Biology (p. 233). Pearson Education. Kindle Edition.

There are five basic tastes—sour, salty, sweet, bitter, and “umami.” Salt is detected when the concentration of salt outside of a taste bud cell is higher than that inside of it, and ion channels allow the passive leakage of Na+ into the cell. The resulting change in membrane potential sends the “salty” signal to the brain. Umami is a savory taste generated by glutamate (glutamic acid, found in monosodium glutamate, or MSG), which is used as a flavor enhancer in foods such as taco-flavored tortilla chips. The glutamate receptor is a GPCR, which, when bound, initiates a signaling pathway that ends with a cellular response, perceived by you as “taste.” If you eat a regular potato chip and then rinse your mouth, you will no longer taste salt. But if you eat a flavored tortilla chip and then rinse, the taste persists. Try it! Propose a possible explanation for this difference.

– People taste umami through taste receptors that typically respond to what?

– What constitute a large protein family of receptors that detect molecules outside the cell and activate internal signal transduction pathways and, ultimately, cellular responses?


Urry, Lisa A.. Campbell Biology. Pearson Education. Kindle Edition.


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