Science — AI-generated practice question

Mouth: Food is chewed and mixed with saliva (secreted by salivary glands). Salivary amylase breaks down starch into simple sugars.

Oesophagus: Food is pushed down to the stomach by peristaltic movements. No digestion occurs here.

Stomach: Gastric glands secrete hydrochloric acid (creates acidic medium), pepsin (digests proteins), and mucus (protects stomach lining).

Small intestine: The main site of digestion. Bile juice from the liver emulsifies fats and makes the medium alkaline. The pancreas secretes pancreatic juice containing trypsin (proteins) and lipase (emulsified fats). Intestinal juice from the intestinal walls finally converts proteins → amino acids, carbohydrates → glucose, fats → fatty acids and glycerol. Digested food is absorbed through villi into the blood.

Large intestine: Water is absorbed from undigested material.

Anus: Remaining waste is expelled via the anal sphincter.

Source: Chapter 5, Section 5.2.4 — Nutrition in Human Beings

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• Examiners expect each organ named with its specific juice/enzyme and action — this is the core of the answer.
• "Emulsification" by bile is a key term; note bile is not an enzyme.
• Mention peristalsis briefly for the oesophagus.
• Villi for absorption in small intestine is often asked separately but fits well here.
• Do not confuse pepsin (stomach) with trypsin (pancreas) — both digest proteins but act in different regions.