| Study Guides
Biology · Unit 3: Cellular Energetics · 5 min read · Updated 2026-05-10

Cellular Energetics Overview — AP Biology

AP Biology · Unit 3: Cellular Energetics · 5 min read

1. Unit at a Glance

This unit builds from foundational energy principles to core cellular processes that support all life. We start with the basics of cellular energy, then move through the structure and function of enzymes—the biological catalysts that power nearly all cellular reactions.

Next, we explore the two complementary energy pathways that sustain life on Earth: photosynthesis, which captures solar energy to build organic molecules, and cellular respiration, which breaks down organic molecules to produce ATP, the cell's usable energy currency. We end by connecting efficient energy processing to evolutionary fitness.

Common Pitfalls

Why: Students mix up goals because the processes have reciprocal reactants and products.

Why: Students often generalize all inhibition as competitive and irreversible.

Why: Students associate plants only with photosynthesis.

Quick Reference Cheatsheet

← Back to topic

Stuck on a specific question?
Snap a photo or paste your problem — Ollie (our AI tutor) walks through it step-by-step with diagrams.
Try Ollie free →