Digestion — Science definition
Breaking food down, mechanically into smaller pieces and chemically into smaller molecules; only the chemical stage makes molecules small enough to absorb.
Where it is taught
- Digestion, Absorption & Food Molecules — Body Organization, Transport & Movement, Life Science & Scientific Inquiry, Grade 7
In use
It was the first direct look at digestion as a chemical process rather than a grinding one.
Digestion, Absorption & Food Molecules
Questions using digestion
Problem 1
Answer and explanation
It changes piece size and surface area but does not necessarily break the relevant chemical bonds into absorbable components.
Problem 2
Answer and explanation
Faster breakdown in B is consistent with increased exposed surface for enzyme contact under the stated conditions. The result is evidence about breakdown rate, not proof that absorption or energy use has already occurred. Further measurements could check the products and their passage across an exchange surface. Other changed conditions would weaken the isolated surface-area explanation.
Identify comparable mass and conditions.
Connect smaller pieces with more exposed surface.
Separate breakdown from later boundary crossing.
Response criteria
- Explain the relevant biological process accurately.
- Use the supplied evidence and show calculation steps with units where needed.
- Connect a labeled model or mechanism with the claim.
- State an assumption, evidence limitation, or useful next observation.