BIOINTERACTIVE Cheat Sheet 2026

The 30 highest-yield BIOINTERACTIVE facts, distilled from real exam questions. Print it, save it as a PDF, or study it here — free, no sign-up.

1. What is the primary function of chloroplasts in plant cells? → Photosynthesis
2. What is photoinhibition? → Reduction in photosynthetic efficiency caused by excess light that damages Photosystem II
3. Where does the Calvin Cycle take place? → Stroma of the chloroplast
4. What role does plastoquinone play in the light reactions? → Electron carrier between Photosystem II and cytochrome b6f
5. How does non-photochemical quenching (NPQ) protect plants from excess light? → It dissipates excess excitation energy as heat to prevent photo-oxidative damage
6. Why is RuBisCO considered an inefficient enzyme? → It has a slow catalytic rate, a dual affinity for both CO2 and O2, and is easily inhibited
7. What color of light is LEAST effective at driving photosynthesis in most plants? → Green
8. What is the overall efficiency of photosynthesis in converting solar energy to glucose? → Typically 1–3% under natural conditions
9. What is an action spectrum in the context of photosynthesis? → A graph showing the rate of photosynthesis at different wavelengths of light
10. What is chlorophyll fluorescence used to assess in photosynthesis? → Photosystem II activity
11. What is the role of RuBisCO activase in photosynthesis? → It reactivates RuBisCO by removing inhibitory sugar phosphates from its active site
12. Why do leaves appear green to human eyes? → Chlorophyll reflects green wavelengths while absorbing red and blue
13. Which plants use CAM photosynthesis? → Cacti and succulents
14. What is the primary pigment in Photosystem II reaction centers? → Chlorophyll a (P680)
15. In what order do electrons flow through the two photosystems during non-cyclic electron flow? → PSII → PSI
16. Which molecule captures light energy during the light reactions? → Chlorophyll
17. What is the primary function of photosynthesis? → Convert light energy into chemical energy
18. What device is commonly used to measure CO₂ uptake during photosynthesis? → Infrared Gas Analyzer (IRGA)
19. What are the two main stages of photosynthesis? → Light-dependent reactions and Calvin Cycle
20. What molecule is regenerated at the end of the Calvin Cycle to allow the cycle to continue? → Ribulose bisphosphate (RuBP)
21. What is the main product of the Calvin Cycle? → Glucose
22. What drives the rotation of ATP synthase in chloroplasts? → Flow of H+ ions from thylakoid lumen to stroma
23. What is the source of electrons that replace those lost by Photosystem II? → Water
24. Which mobile electron carrier transfers electrons from Photosystem II to the cytochrome b6f complex? → Plastoquinone
25. What is the key advantage of CAM over C3 photosynthesis in desert environments? → Stomata open only at night, dramatically reducing water loss
26. What is the significance of the RuBP regeneration step in the Calvin cycle for maintaining photosynthetic rate? → If RuBP is not regenerated, the Calvin cycle stops and CO2 cannot be fixed
27. Which parameter represents the total CO₂ fixed during photosynthesis without accounting for respiration? → Gross photosynthetic rate
28. Which structure within the chloroplast contains chlorophyll? → Thylakoid membrane
29. What is the main purpose of the Calvin Cycle? → Fix carbon dioxide into glucose
30. Where are both Photosystem I and Photosystem II located within the chloroplast? → Thylakoid membrane