Question

Acid neutraliser present in mucus of saliva is
A. Bicarbonate ion
B. Thiocyanate
C. Sodium acetate
D. Sodium hydroxide

Answer 1

Saliva (typically called spit) is an extracellular fluid produced and secreted using salivary glands within the mouth. In people, saliva is 99.5⁠ percent water plus electrolytes, mucus, white blood cells, epithelial cells (from which DNA can be extracted), enzymes (which includes amylase and lipase), antimicrobial marketers together with secretory IgA, and lysozyme.

Complete answer: Saliva includes bicarbonate, phosphate, proteins, and so forth. They act as buffers to hold the salivary pH in the ordinary limits. Decreased pH predisposes to caries whereas an increase in pH may be accountable for tartar cloth and destroys the alveoli gingival margin. Produced in salivary glands, human saliva accommodates 99.5% water, however additionally consists of many critical substances, which include electrolytes, mucus, antibacterial compounds, and various enzymes. Since saliva incorporates 99.5 percent water and daily secretion of saliva is 1 litre or more, the lower body water content decreases salivary secretion and outcomes in thirst sensation. Salivary amylase or ptyalin is a carbohydrate splitting enzyme. It acts at a pH of 6.8. It can act best on starch. When the starch is boiled, the cellulose overlaying of starch granules ruin and amylase can penetrate cellulose. Saliva is a buffering agent because of the presence of bicarbonate ions. Bicarbonate ions are primary, therefore, act in opposition to acid and consequences in the neutralization of acid.
Hence, Option A is correct, i.e., Bicarbonate ion is the correct answer.

Note: Several substances may be excreted in saliva, like Heavy metals like mercury, lead, iodides, alkaloids like morphine, antibiotics like penicillin, streptomycin, microorganisms like viruses causing mumps, measles, polio, etc. But the maximum of the instances, the saliva formed is being swallowed. Thus it could no longer serve a lot of excretory function. It additionally helps in speech.