B1.1.3—Digestion by hydrolysis
Hydrolysis uses water to break covalent bonds in food macromolecules, producing soluble monomers that can be absorbed and reused by cells.
- Syllabus
- First assessment 2025
- Objective
- B1.1.3
- Level
- HL
Exam analysis
Chance of appearing6%of analysed past papers
Latest appearanceMay 2024
Most common paperPaper2
Typical marks1–4
Common command terms
- State
- Outline
- Describe
- Explain
- Identify
Scoring notes
- Common mistake
- Confusing hydrolysis with condensation when identifying reaction type.
Recent exam appearances
May 2024Paper1 ["HL"] · TZ124[ 1 ]B1.1.3—Digestion by hydrolysis
May 2022Paper2 ["HL"] · TZ26(c)[ 4 ]B1.1.3—Digestion by hydrolysis
May 2021Paper2 ["HL"] · TZ15(c)[ 2 ]B1.1.3—Digestion by hydrolysis
November 2020Paper2 ["HL"] · TZ06(b)[ 4 ]B1.1.3—Digestion by hydrolysis
November 2018Paper2 ["HL"] · TZ02(b)[ 2 ]B1.1.3—Digestion by hydrolysis
Practice this objective
Coverage 2015–2024 · Updated 15 Jul 2026
Concept essentials
- Hydrolysis breaks covalent bonds by adding water.
- Digestion converts macromolecules into smaller soluble products for absorption.
- Amylase, proteases and lipase catalyse hydrolysis of different food molecules.
- Products of digestion can be absorbed through the small intestine.