AP Biology · Unit 3
Cellular Energetics
Investigate how enzymes control reactions and how cells capture, transfer, and use energy through photosynthesis and cellular respiration.
Learning sequence
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Topic 3.1
Enzymes Lower the Barrier
Connect active-site structure, activation energy, specificity, and saturation to reaction rate.
Topic 3.2
When Conditions Change
Analyze temperature, pH, concentration, inhibitors, controls, and replicated enzyme data.
Topic 3.3
Energy, Coupling & Pathways
Trace energy through ATP coupling, sequential pathways, and conserved metabolism.
Topic 3.4
Light Reactions
Follow electrons and protons through thylakoids to ATP, NADPH, and oxygen.
Topic 3.4
Carbon Fixation & Limiting Factors
Connect chloroplast structure, carbon fixation, wavelengths, and environmental rate data.
Topic 3.5
Cellular Respiration
Track carbon, electrons, ATP, oxygen, chemiosmosis, and fermentation.
Topics 3.1–3.5
Unit 3 Assessment
Apply energetics concepts to models, calculations, perturbations, and experimental evidence.