Changes during Digestion

(a) Starch:

1. Mouth: Salivary glands in the mouth release an enzyme called amylase that starts breaking down starch into smaller sugars.

2. Stomach: The acidic environment in the stomach stops the action of amylase.

3. Small intestine: Pancreatic juice and intestinal juice are released in the small intestine. These juices contain enzymes that break down starch into glucose, which is then absorbed by the bloodstream.

(b) Fats:

1. Mouth: Saliva contains an enzyme called lipase, which starts breaking down fats into fatty acids and glycerol.

2. Stomach: The stomach churns and mixes the food, breaking down fats into smaller droplets.

3. Small intestine: Bile released from the liver helps to emulsify fats, breaking them down into smaller droplets. Pancreatic juice contains enzymes that break down fats into fatty acids and glycerol.

(c) Proteins:

1. Stomach: The stomach releases hydrochloric acid, which denatures proteins, making them easier to break down.

2. Stomach: Pepsin, an enzyme released by the stomach, breaks down proteins into smaller polypeptides.

3. Small intestine: Pancreatic juice and intestinal juice contain enzymes that further break down polypeptides into amino acids.

Conclusion:

During digestion, starch is broken down into glucose, fats are broken down into fatty acids and glycerol, and proteins are broken down into amino acids. This breakdown process begins in the mouth and continues in the stomach and small intestine with the help of various enzymes and juices. The end result is the absorption of nutrients into the bloodstream for use by the body.

Starch