Formative Practice 9.1 (Form 4 Biology Textbook Exercise and Answer)

Question 1:
Explain the importance of the digestion process for humans.

The food consumed by humans is in the form of large and complex molecules. The food needs to be broken down to a smaller and simpler form that can diffuse into the blood vessels and transported to body cells.

Question 2:
Name the structures in the alimentary canal that are involved in food digestion.

The structures that are involved in the digestion process are mouth, teeth, oesophagus, stomach, duodenum, small and large intestines.

Question 3:
Name the main cells in the gastric glands and explain the functions of these cells.

The main cells in gastric glands are chief cells that secrete pepsinogen, parietal cells that secrete hydrochloric acid and goblet cells that secrete mucus.

Question 4:
The small intestine secretes a few types of enzymes to complete the digestion process. Explain how these enzymes complete the digestion process.

The enzymes that are involved in the digestion process in the small intestine are trypsin, amylase, erepsin, sucrose, maltase, lactase and lipase.

Function of enzyme:
Trypsin—hydrolyses polypeptide to peptide
Amylase—hydrolyses starch to maltose
Erepsin—hydrolyses peptides to amino acids
Sucrase—hydrolyses sucrose to glucose and fructose
Maltase—hydrolyses maltose and glucose
Lactase—hydrolyses lactose to glucose and galactose
Lipase—hydrolyses lipids to fatty acids and glycerol

Leave a Comment