Final answer:
Saliva has multiple functions including moistening and lubricating the mouth, dissolving food, cleaning the mouth and teeth, and breaking down starches with the enzyme amylase.
Step-by-step explanation:
The functions of saliva include:
- Moistening and lubricating the lining of the mouth and pharynx
- Moistening, softening, and dissolving food
- Cleaning the mouth and teeth
- Breaking down starches with the enzyme amylase
Saliva is primarily composed of water, but it also contains enzymes, ions, glycoproteins, and waste products. The enzyme salivary amylase is important for the breakdown of carbohydrates. Saliva also helps with the movement and swallowing of food, and it has antimicrobial properties to protect the mouth.
Functions of saliva indeed include cleansing the mouth, dissolving food, and aiding in the formation of a food bolus. Crucially, it also starts the breakdown of starches thanks to the enzyme salivary amylase. This enzyme specifically targets carbohydrates, and not proteins as incorrectly stated in option a. The process is initiated in the mouth and continues until the enzyme is inactivated by the acidic environment of the stomach.
Saliva serves to moisten and lubricate the lining of the mouth and pharynx, making the process of chewing and swallowing easier. It's composed mostly of water, but the remaining constituents, including ions, glycoproteins, enzymes like amylase and lysozyme, growth factors, and immunoglobulins play significant roles in oral health and digestion. The mucus-helps facilitates the movement and compaction of food into the bolus, while the enzymes start the chemical digestion of food.