Physical digestion and teethSpec B7.3.1, B7.3.3
In short
Physical digestion breaks food into smaller pieces; incisors cut, canines tear, and premolars and molars crush and grind. Cambridge IGCSE Biology 7.3.
Physical digestion is the breakdown of food into smaller pieces without chemical change to the food molecules.
Supplement (what this means)
Supplement: only for the Extended papers (2 and 4). Core students can skip it. What the labels meanPhysical digestion increases the surface area of the food, so enzymes in chemical digestion can act on more of it at once.
Written and checked against the Cambridge IGCSE Combined Science (0653) specification · Updated October 2026