Question

State, in brief, the function of digestive enzymes.

Answer 1

The process involves ingesting food and using it to derive chemical energy molecules for cellular metabolic processes. It is divided into several nutritional stages. These nutritional stages convert complex molecules into simple molecules by the action of enzymes for better assimilation.

Complete answer:
Nutrition in humans is divided into five nutritional stages which are as follows:
a) Ingestion: In this process, the food is chewed and ground and the bolus formed is swallowed which travels through the oesophagus by peristalsis and reaches the stomach.
b) Digestion: The complex substances are broken down into simpler ones with the help of several enzymes that can be assimilated into the body tissues. The enzymes are categorised into four types based on the molecule they act upon:
i) Carbohydrases: These are enzymes that help in the digestion of carbohydrates such as amylases.
ii) Proteinases: These enzymes help in the breakdown of proteins such as pepsin.
iii) Lipases: These enzymes breakdown lipids into fatty acids and glycerol such as gastric lipase.
iv) Nucleases: These enzymes help in the breakdown of nucleic acids.
c) Absorption: Absorption mainly occurs in the small intestine since it has finger-like projections known as villi that increase the surface area for the absorption of nutrients.
d) Assimilation: After digestion and absorption, chemicals from the food are taken into the cells of the body. The nutrients are transported by the blood to the required cells of the body.
e) Egestion: Egestion is the process of removal of undigested food materials in form of faeces from the anus.

Note: The process of obtaining nutritive substances and then using it for the production of chemical energy currencies that can be used for several metabolic processes such as growth and repair of the body is known as nutrition. It is divided into several stages and it takes place in the alimentary canal of the body.