AP Biology · Unit 3
Cellular Energetics
In short
Unit 3: Cellular Energetics in AP Biology covers 5 topics: Enzymes, Environmental Impacts on Enzyme Function, Cellular Energy, Photosynthesis and 1 more. Open each one for what you need to know, a self-check list and how it is tested on the exam.
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What is in Unit 3: Cellular Energetics?
Unit 3: Cellular Energetics
3.1 Enzymes
- I can explain how enzymes act as biological catalysts by lowering the activation energy of chemical reactions.
- I can describe how the shape and charge of a substrate must be compatible with an enzyme's active site to form an enzyme-substrate complex.
3.2 Environmental Impacts on Enzyme Function
3.3 Cellular Energy
- I can state that all living systems require an input of energy.
- I can explain that life requires a highly ordered system, and that energy input must exceed energy loss to maintain order and power cellular processes.
- I can describe how energy-related pathways are sequential, allowing for controlled energy transfer where the product of one reaction is typically the reactant for the next.
- I can explain how core metabolic pathways, such as glycolysis and oxidative phosphorylation, are conserved across all domains of life and support the concept of common ancestry.
3.4 Photosynthesis
- I can explain that photosynthesis uses carbon dioxide, water, and light energy to make carbohydrates and oxygen, and describe its evolutionary origins in prokaryotes.
- I can identify the stroma and thylakoids within the chloroplast and describe their roles in the Calvin cycle and light reactions.
- I can describe how the light reactions capture energy to yield ATP and NADPH, which power the Calvin cycle.
- I can describe the role of the electron transport chain in chloroplasts and how electrons are transferred to NADP+ to form NADPH.
- I can explain how chlorophylls absorb light energy to boost electrons in photosystems I and II, and how water is split to replace electrons.
- I can describe how photosystems I and II are embedded in the thylakoid membrane and connected by an ETC.
- I can explain how the transfer of electrons through the ETC establishes an electrochemical gradient of protons across the thylakoid membrane.
- I can explain how the proton gradient drives the synthesis of ATP via ATP synthase through chemiosmosis (photophosphorylation).
- I can describe how the energy from ATP and NADPH is used in the Calvin cycle to produce carbohydrates from carbon dioxide in the stroma.
3.5 Cellular Respiration
- I can state that cellular respiration and fermentation use energy from biological macromolecules to synthesize ATP and are characteristic of all forms of life.
- I can describe how aerobic cellular respiration involves a series of coordinated enzyme-catalyzed reactions that capture energy.
- I can explain how the electron transport chain establishes an electrochemical gradient, how chemiosmosis drives ATP formation, and how decoupling generates heat.
- I can describe glycolysis as a pathway that releases energy from glucose to form ATP, NADH, and pyruvate.
- I can explain the transport of pyruvate to the mitochondrion and its oxidation during the Krebs cycle to release CO2, NADH, and FADH2.
- I can describe the Krebs cycle's role in releasing carbon dioxide, synthesizing ATP, and transferring electrons to coenzymes.
- I can trace the transfer of electrons from glycolysis and the Krebs cycle to the ETC via NADH and FADH2.
- I can explain how electron transfer through the ETC establishes a proton gradient across the inner mitochondrial membrane.
- I can describe how fermentation allows glycolysis to continue in the absence of oxygen by producing organic molecules such as alcohol or lactic acid.
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Cellular Energetics: common questions
What is in Unit 3: Cellular Energetics?
It covers 5 topics: 3.1 Enzymes; 3.2 Environmental Impacts on Enzyme Function; 3.3 Cellular Energy; 3.4 Photosynthesis; 3.5 Cellular Respiration.
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