Question

What is digestion? Explain the process of digestion in the mouth cavity and stomach

Answer 1

Digestion is the process of breakdown of large molecules of food into simpler, soluble substances that can be absorbed by the body. In the mouth, the food is chewed and mixed with saliva, secreted by the salivary glands. The saliva helps lubricate the food and also contains enzymes such as salivary amylase that helps in breaking down starch into its simpler forms such as maltose. In the stomach, the food is mixed with HCl, secreted by the chief cells and digestive enzymes. HCl helps provide an acidic environment and also helps kill bacteria and other microorganisms that may be digested along with the food. Mucous glands lining the stomach secrete mucous that prevents the stomach walls from being damaged by the effects of HCl. In the stomach the enzyme pepsinogen is secreted by the parietal cells, that is converted into pepsin under the effects of HCl and it helps in the breakdown of proteins into peptones and peptides.