What is the work of the following enzymes and related digestive processes?

Here are the answers to the questions:

43. What is the work of the following enzymes?

• Salivary amylase: Breaks down complex carbohydrates (starch) into simpler sugars (maltose).
• Pepsin: Breaks down proteins into smaller polypeptides in the stomach.

44. Write down another name for salivary amylase.

• Ptyalin

45. Briefly state role rennin plays in digestion?

• Rennin (chymosin) curdles milk protein (casein) in the stomach of infants, allowing for slower digestion.

46. Write down the work of the following enzymes.

• a) Amylase: Breaks down starch into simpler sugars.
• b) Trypsin: Breaks down proteins and polypeptides into smaller peptides in the small intestine.
• c) Lipase: Breaks down fats (lipids) into fatty acids and glycerol.

47. What role does bile play in digestion?

• Bile emulsifies fats, breaking large fat globules into smaller ones, which increases the surface area for lipase to act upon. It also neutralizes acidic chyme from the stomach.

48. Why is emulsification of fats important?

• Emulsification increases the surface area of fat droplets, allowing digestive enzymes (lipases) to break them down more efficiently into fatty acids and glycerol for absorption.

49. State the enzymes which converts proteins into amino acids.

• Proteases (like trypsin and chymotrypsin) break proteins into smaller peptides, and then peptidases (like aminopeptidase and dipeptidase) further break these peptides into individual amino acids.

50. What major activities place in the small intestine (ileum)?

• The ileum is primarily responsible for the absorption of digested nutrients, including vitamin B12, bile salts, and any remaining nutrients not absorbed in the jejunum.

51. List four adaptations of the small intestine for the process of food absorption.

• Long length: Provides ample time and surface area for digestion and absorption.
• Villi: Finger-like projections that greatly increase the inner surface area.
• Microvilli: Tiny projections on the surface of villi cells (forming a brush border) that further increase surface area.
• Rich blood supply: Each villus contains a capillary network and a lacteal to transport absorbed nutrients away quickly.