Class 10 Biology
NCERT Exercise Solution
How are fats digested in our bodies? Where does this process take place?
Answer: Fats are present in the intestine in the form of large globules which makes it difficult for enzymes to act on them. Bile salts break them down into smaller globules increasing the efficiency of enzyme action. The pancreas secretes pancreatic juice which contains enzyme called lipase for breaking down emulsified fats. The walls of the small intestine contain glands which secrete intestinal juice. The enzymes present in it finally convert fats into fatty acids and glycerol.
Describe double circulation in human beings. Why is it necessary?
Answer: In double circulation there is complete segregation of oxygenated and deoxygenated blood. Because of this the blood passes twice through the heart in one cycle of circulation hence the name double circulation.
This is necessary for optimum oxygen utilization as humans are warm blooded animals and need extra energy to maintain their body temperature.