Chapter 54 Flashcards
For sodium ions and hydrogen ions, which elicit salty and sour taste sensations, respectively, the receptor proteins open specific ion channels which are likely the:
epithelial sodium channel (ENaC)
For the sweet and bitter taste sensations, the portions of the ___________ receptors that protrude through the apical membranes are activated
G-protein coupled receptors
This is the co-receptor for sweet and umami tastes.
T1R3
Sweet-tasting compounds are detected by a combination of two closely related G-protein-coupled taste receptors:
T1R2 and T1R3
The receptors responsible for umami taste is believed to be a complex of:
T1R1 and T1R3
Bitter taste is sensed by another family of receptors, the _____, of approximately 30 different G-protein coupled receptors.
T2R
“Btworrr”
2 channels responsible for mediating acid responses in taste receptor cells
acid-sensitive potassium channel (KIR2.1)
hydrogen ion-selective ion channel
The taste sensation of bitter is cause by many substances that contain ____, as well as by ____
nitrogen
alkaloids
Umami is the dominant taste of food containing ______, such as meat extracts and aging cheese
l-glutamate
Some people are taste blind for certain substances, especially for different types of thiourea compounds. A substance used frequently by psychologists for demonstrating taste blindness is ____________, for which about 15% to 30% of all people exhibit taste blindness; the exact percentage depends on the method of testing and the concentration of the substance.
phenylthiocarbamide
From the tip of each taste cell, several _______ protrude outward into the taste pore to approach the cavity of the mouth. These provide the receptor surface for taste.
microvilli, or taste hairs
Which taste sensation is most likely to be the most sensitive (i.e., has the lowest stimulation threshold)?
bitter
