Question

People who lose their sense of taste may also lose interest in eating. Which of the following is involved in the perception of tastes?

Taste cells for sweet are only located at the anterior tip of the tongue.
Transduction of sour and sweet tastes involves activation of a G protein called gustducin.
Afferent impulses related to taste are carried to from the tongue to the CNS by the trigeminal nerve (cranial nerve V).
Much of what is perceived as a taste defect may actually be a defect in olfaction, which causes foods and beverages to taste differently.

Answer 1

Answer: Transduction of sour and sweet tastes involves activation of a G protein called gustducin.

Explanation: The correct option is "Transduction of sour and sweet tastes involves activation of a G protein called gustducin." This option correctly describes the process of transduction, which is the conversion of a sensory stimulus into an electrical signal that can be interpreted by the brain. Gustducin is a type of G protein that is involved in the transduction of sweet and umami (savory) tastes, as well as sour tastes to some extent. Therefore, this option is directly involved in the perception of tastes.

Option A is incorrect because taste cells for sweet are not only located at the anterior tip of the tongue; rather, they are spread throughout the tongue. Option C is incorrect because afferent impulses related to taste are carried to the CNS by three different cranial nerves - facial (VII), glossopharyngeal (IX), and vagus (X) - and not trigeminal nerve (V). Option D is partially correct because olfaction does play a role in taste perception, but it does not explain the specific mechanism of taste transduction as mentioned in option B.