College Board-Aligned Original Notes

AP Biology Unit 3 Topic 1: The structure and function of enzymes

Connect The structure and function of enzymes to a model, the evidence that supports it, and the variables that change the system.

Unit 3: Cellular Energetics. College Board exam weighting listed for this unit: 12%-16% of exam score.

What to Know

Identify the system, surroundings, and scale before explaining a process.
Use diagrams, graphs, and tables as evidence rather than decoration.
For quantitative questions, keep units visible from the setup through the final answer.
Always connect this topic back to the larger unit: Cellular Energetics.

Detailed Notes

The structure and function of enzymes belongs to Cellular Energetics, so study it as part of a larger scientific system rather than as a stand-alone fact. Start by identifying what is being described, what is changing, and what evidence would let you defend a claim.

In AP Biology, strong answers usually connect a visible pattern to an underlying mechanism. That means explaining not only what happens, but why it happens at the particle, organism, environmental, or system level.

For AP-style questions, expect this topic to appear with graphs, diagrams, data tables, experiments, or written scenarios. Your job is to describe the evidence, apply the correct concept, and explain the reasoning that connects them.

Key Vocabulary

Enzyme

A biological catalyst that speeds up a chemical reaction.

Active site

The region of an enzyme where the substrate binds.

Substrate

The reactant that an enzyme acts on.

Denaturation

A change in a protein's shape that can reduce or destroy its function.

Quick Practice

How would you explain The structure and function of enzymes in one or two AP-style sentences?

Name the concept, apply it to a specific example or source, and explain the reasoning that connects the evidence to your answer.