Science (086) — AI-generated practice question

Mouth: Food is chewed and mixed with saliva. Salivary amylase acts on starch; proteins are not digested here.

Stomach: Gastric glands secrete hydrochloric acid (creates acidic medium) and the enzyme pepsin. Pepsin partially digests proteins into peptides. Mucus protects the stomach lining.

Small intestine: The pancreas secretes trypsin, which further digests proteins/peptides. The intestinal glands secrete intestinal juice whose enzymes finally break down proteins completely into amino acids.

Absorption: The inner lining of the small intestine has numerous finger-like projections called villi, which greatly increase the surface area for absorption. Villi are richly supplied with blood vessels; amino acids are absorbed directly into the blood capillaries and transported to all cells of the body.

Source: Life Processes, Section 5.2.4

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• Examiners expect a stage-by-stage account: mouth → stomach → small intestine → absorption.
• Name both organ and enzyme at each stage — pepsin (stomach), trypsin (pancreas/small intestine), intestinal enzymes → amino acids.
• HCl's role (activating pepsin / providing acidic medium) is a common 1-mark point — include it.
• For absorption, mention villi, blood vessels, and the end-product (amino acids) — all three are typically needed for full marks.
• Do not confuse trypsin (pancreatic) with pepsin (gastric); examiners penalise mixing these up.