Question

Which of the following statements accurately describes saliva?

A. Saliva contains bile salts that emulsify fats
B. Saliva contains enzymes and proteins that initiate chemical digestion of food
C. Saliva contains enzymes that break down chyme
D. Saliva contains hydrochloric acid and enzymes that digest food into chyme

Answer 1

Saliva contains salivary amylase, an enzyme that initiates the breakdown of carbohydrates, and is comprised mostly of water, as well as enzymes and proteins that start the chemical digestion of food.

Step-by-step explanation:

The statement that accurately describes saliva is that it contains enzymes and proteins that initiate the chemical digestion of food. Specifically, saliva contains an enzyme called salivary amylase, which begins the chemical digestion in the mouth by breaking down carbohydrates. Saliva does not contain bile salts, hydrochloric acid, or enzymes that break down chyme.

The extensive chemical process of digestion begins in the mouth, where the saliva produced by the salivary glands mixes with food, moistening it and converting starches into a disaccharide called maltose through the action of salivary amylase. Another enzyme, lipase, is produced by cells in the tongue and begins the breakdown of fats.

The composition of saliva is mostly water, but it also contains bicarbonate and phosphate ions that function as chemical buffers, mucus to lubricate food, immunoglobulin A to prevent microbial penetration, and lysozyme to provide antimicrobial action.