Question

When I was suffering from a lot of phlegm in my throat, one of my students recommended I take a shot of apple cider vinegar, which was quite sour. The transduction process that enabled me to taste it was initiated by

A. sodium ions traversing the apical plasma membrane of my taste cells.

B. protons traversing the apical plasma membrane of my taste cells.

C. calcium-mediated activation of voltage-gated Na+ channels.

D. calcium-mediated activation of Cl- channels.

Answer 1

taste receptors are specialised sensory receptors which help in poroviding the taste of the food as the papillae within the taste buds contain speialised gustatory receptors which help in the transduction of taste stimuli. the transduction process occurs through the voltage gated ion channels present on the apical and basolateral membrane of the taste cells.

the receptors respond to the chemicals present in food in different ways. the receptors for salt are present on the apical membrane of the taste cells and are epithelial -type sodium channels.the presence of sodium leads to the depolarisation of the relevant taste cells. greater the concentration of the tasteant , greater is the depolarisation.

protons can also diffuse through the ion channels but there movement is quite slow than sodium ions. The presence of lemon jiuce in the salty food reduces the salt taste, as protons are primarily responsible for sour taste and they interact with the specific receptors present on distinct location of the apical membranes of taste cells.

thus option B is correct as sour taste receptors are proton mediated channels while salty food receptors are voltage gated sodium channels.