AP Exam Prep · AP Biology
AP Biology Unit 1 Practice Test: Chemistry of Life
Unit 1 explains how the chemistry of water and carbon-based molecules makes life possible. You need to connect a molecule's structure to what it does: why water sticks to itself, which elements end up in which macromolecules, and how a protein's amino acid sequence decides its shape.
- Exam weighting:
- 8–11%
- Questions:
- 12 multiple choice
- Time:
- about 16 minutes
- Cost:
- Free, no sign-up
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What AP Bio Unit 1 covers
Unit 1, Chemistry of Life, makes up 8–11% of the multiple-choice section and usually takes ~9–11 class periods. These are the topics in the current course framework, and every question in the test above is tagged with one of them.
- 1.1Structure of Water and Hydrogen Bonding
- 1.2Elements of Life
- 1.3Introduction to Macromolecules
- 1.4Carbohydrates
- 1.5Lipids
- 1.6Nucleic Acids
- 1.7Proteins
Unit 1 key ideas
Water's properties come from hydrogen bonds
Water is polar, so neighbouring molecules form hydrogen bonds. Those bonds explain cohesion, adhesion, surface tension, high specific heat and why water dissolves other polar and charged substances.
Elements are recycled into specific molecules
Carbon, hydrogen and oxygen are in every macromolecule. Nitrogen is needed for proteins and nucleic acids, phosphorus for nucleic acids and phospholipids, and sulfur for some amino acids.
Polymers are built and broken with water
Dehydration synthesis links monomers and releases water. Hydrolysis adds water to break those bonds. The type of bond (glycosidic, ester, phosphodiester, peptide) depends on the macromolecule.
Structure determines function
Small changes in structure, such as the linkage in a carbohydrate, a double bond in a fatty acid, or one amino acid in a protein, can change shape, properties and function.
Common Unit 1 mistakes
- Mixing up hydrogen bonds (between molecules) with covalent bonds (within a molecule).
- Reversing dehydration synthesis and hydrolysis.
- Forgetting that DNA strands are antiparallel when writing a complementary sequence.
How to study this unit
- For each macromolecule, learn its monomer, the bond that links monomers, the elements it contains and one structure–function example.
- Practise explaining a property of water in two steps: the hydrogen bonding, then the consequence for living things.
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About these questions
StudyCoach wrote these questions for this test. Each one is mapped to a topic in the College Board's current AP Biology course framework. Every answer key was also checked by a separate AI review, and any disagreement was rechecked by hand. They have not yet been reviewed by an AP Biology teacher. If you think an answer is wrong, email support@studycoach.io.
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