All of the following are the constituents of human saliva EXCEPT

Explanation

The correct answer is sucrose. Human saliva contains mucus to lubricate the mouth, amylase to begin the digestion of starches, and sodium bicarbonate to help neutralize acids. Sucrose, however, is not naturally found in saliva; it is a sugar that is introduced to the mouth through food and drink. The other options, mucus, amylase, and sodium bicarbonate, are all natural components of saliva with specific functions.