A sour taste in your mouth.Think of all the amazing things that your tongue does for you. Specialized cells on your tongue, for example, give you the power to enjoy (and gag at) the spices and other flavors of the world's cuisines. For years, scientists have been investigating the cells that allow us to detect five distinct tastes: salty, sweet, bitter, sour, and umami For the record label, see . Umami (Japanese: 旨み、旨味、うまみ) is one of the five basic tastes sensed by specialized receptor cells present on the human tongue. . Umami describes the taste of a substance called monosodium glutamate monosodium glutamate: see glutamic acid. monosodium glutamate (MSG) White crystalline substance, a sodium salt of the amino acid glutamic acid. MSG is used to intensify the natural flavour of meats and vegetables. (MSG MSG: see glutamic acid. ). So far, sweet, bitter, and umami are pretty well understood. The other two have remained mysterious. How does your tongue detect the sour taste of a lemon? Now, at long last, researchers may have discovered the secret behind the puckering flavor of lemons, vinegar, and sour gummy gummy an old sheep that has lost all of its incisor teeth. candy. One protein, called PKD Noun 1. PKD - kidney disease characterized by enlarged kidneys containing many cysts; often leads to kidney failure polycystic kidney disease kidney disease, nephropathy, renal disorder, nephrosis - a disease affecting the kidneys 2L1, might do the trick. To decode the sour system, the scientists started by assuming that sour-sensing proteins would share basic traits with proteins that allow us to sense other tastes. In general, these molecules, called receptors, are embedded inside certain tongue cells. Also, each tongue cell contains a receptor that senses just one type of flavor. One cell might have a sweet receptor, for instance, while another cell responds only to bitter flavors. The scientists zeroed in on PKD2L1. This protein caught their eye because it appeared to be a specialized protein in taste bud taste bud n. One of a number of flask-shaped receptor cell nests located in the epithelium of the papillae of the tongue and in the soft palate, epiglottis, and pharynx that mediate the sense of taste. cells. At the same time, it did not show up in cells that sensed sweet, bitter, or umami flavors. The researchers then created a strain of mice that did not make the PKD2L1 protein. Tests of the animals' nerves showed that the mice continued to respond to all flavors except sour ones. When the scientists gave them sour chemicals, such as citric acid or vinegar, nothing happened. The mice "were completely insensitive, just like we were dabbing their tongues with water," says research-team leader Charles S. Zuker of the University of California, San Diego UCSD is consistently ranked among the top ten public universities for undergraduate education in the United States by U.S. News & World Report.[3] It is a Public Ivy. [1] For graduate studies, most of UCSD's Ph.D. . The discovery may eventually help chemists make foods more or less sour, from the inside out. Here's what I'd like to know next: Why do some people like to eat sour candy? I'm not a fan, and I never will be, but I know people who love it. The mysteries of science never cease to amaze me! http://www.sciencenewsforkids.org/articles/20060830/Note3.asp From Science News for Kids Aug. 30, 2006. |
|
||||||||||||||||||||
Printer friendly
Cite/link
Email
Feedback
Reader Opinion