state the role of the following in human digestive system
a. digestive enzymes
b. vili
c. hydrochloric acid.
Answers
Answer: (a)Digestive enzymes play a key role in breaking down of foods.
(b) Villi are finger like projections of the small intestine.
(c)Hydrochloric acid is a highly corrosive strong mineral acid in aqueous solution
Answer:
(i) Digestive enzymes – Foods need to be broken into their small or simpler
molecules so that they can be absorbed into the bloodstream. However, the physical breakdown of food is not enough. Enzymes are hence needed for the chemical breakdown of food and speeding up the digestive process. The products of digestion can hence be small enough to be absorbed.
(ii) Hydrochloric acid – Hydro chloric acid helps to kill the germs which might have entered in to the system through food. It creates acidic medium for the pepsin to act on food to breakdown proteins.
(iii) Villi – Villi are finger like projections in the small intestine. They help to increase the surface area for absorption of the digested food. Villi are richly supplied with blood vessel which help to absorb digested food in to the blood stream.
Explanation: