Photosynthesis Cheat Sheet 2026
The 30 highest-yield Photosynthesis facts, distilled from real exam questions. Print it, save it as a PDF, or study it here — free, no sign-up.
- During state transitions in chloroplasts, what happens when light preferentially excites PSII? → LHCII migrates from grana to stroma lamellae to balance excitation between photosystems
- Which component of the thylakoid membrane directly uses the proton gradient to synthesize ATP? → ATP synthase (CF1-CF0)
- What is the primary function of plastocyanin in the light reactions? → To transfer electrons from the cytochrome b6f complex to Photosystem I
- Euglenoids are unique photosynthetic protists because they: → Can switch between autotrophy and heterotrophy
- Which experiment provided direct evidence that oxygen released in photosynthesis comes from water, not CO2? → Van Niel's comparison of purple sulfur bacteria using H2S
- What molecule serves as the carbon dioxide acceptor in the CAM pathway during nighttime fixation? → Phosphoenolpyruvate (PEP)
- How does documentation support quality in Chloroplast Structure? → It creates records, ensures consistency, and enables improvement
- Chloroplasts are thought to have originated through a process called: → Endosymbiosis
- What role does ethics play in Energy Conversion practice? → It guides professional conduct and protects stakeholders
- Which of the following molecules is regenerated at the end of the Calvin cycle to allow continued carbon fixation? → Ribulose-1,5-bisphosphate (RuBP)
- Which term describes the ATP-powered movement of protons across the thylakoid membrane that drives ATP synthesis? → Photophosphorylation
- Which study approach is most effective for Calvin Cycle material? → Active recall with practice questions
- What is the role of the oxygen-evolving complex (OEC) in the light reactions? → It splits water molecules to release oxygen
- Which of the following is NOT required for the process of photosynthesis? → Oxygen
- What is the primary photosynthetic pigment in brown algae (phaeophytes)? → Fucoxanthin
- What is the function of the antenna complex in a photosystem? → Absorb and transfer light energy to the reaction center
- How does increased CO₂ concentration generally affect the rate of photosynthesis? → It increases the rate up to a point where other factors become limiting
- What is the primary reason that photosynthesis decreases at very high light intensities beyond the saturation point? → The rate-limiting step shifts to CO₂ availability and enzyme capacity, not light
- What is the relationship between theory and practice in Environmental Factors? → Theory provides the foundation; practice applies it to real situations
- What is the primary advantage of C4 carbon fixation over C3 fixation in hot, dry environments? → It concentrates CO₂ around RuBisCO, reducing photorespiration
- How does supplemental CO2 enrichment in commercial greenhouses improve crop yield? → It directly increases the rate of the Calvin cycle
- How many ATP molecules are produced per FADH2 via oxidative phosphorylation? → ~1.5 ATP
- The term 'autotroph' refers to an organism that: → Produces its own organic molecules from inorganic sources using light or chemical energy
- During the daytime in CAM plants, accumulated malate is decarboxylated to release CO2, which then enters which pathway? → The Calvin cycle (light-independent reactions)
- C4 plants minimize photorespiration primarily by doing what? → Concentrating CO₂ around RuBisCO in bundle sheath cells
- How does increased soil salinity negatively affect photosynthesis? → It causes osmotic stress that reduces water uptake
- Which study approach is most effective for Light Reactions material? → Active recall with practice questions
- Which study approach is most effective for Chloroplast Structure material? → Active recall with practice questions
- Oligomycin blocks the F0 channel of ATP synthase. What happens to the proton gradient? → The proton gradient increases because protons can no longer flow back through ATP synthase
- Why is photosynthesis important for maintaining life on Earth? → It produces oxygen, which is essential for aerobic organisms.
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