Question

Which of the following is associated with bitter tasting solute?

• A. Hydrophilic quinine
• B. Toxic alkaloid
• C. Nontoxic alkaloid
• D. All of the above

Answer 1

Answer: (D)

All of the above

Bitter tasting solutes include many non-toxic and toxic alkaloids, hydrophilic quinine and some divalent ions. The threshold for stimulation of bitter taste by quinine averages a concentration of 8 μM (8 micromolar). The taste thresholds of other bitter substances are rated relative to quinine, which is thus given a reference index of 1.