Question

hich corrections would change the diagram to accurately model the light-dependent reaction of photosynthesis? Check all that apply.

CO2 should be changed to H2O.
ADP and ATP need to be switched.
e– should be changed to H+.
Chemical energy should be changed to light energy.
PSII and PSI need to be switched.

Answer 1

Check these four corrections:

- Change CO2 to H2O — the light reactions use water (H2O) as the electron source and produce O2; CO2 is fixed in the Calvin cycle (light‑independent reaction).
- Switch ADP and ATP — ADP + Pi is converted to ATP by ATP synthase during the light reactions, so the labels should reflect ADP → ATP, not the reverse.
- Change e– to H+ where appropriate — protons (H+) flow through ATP synthase to drive ATP production; electrons move through the electron transport chain and to NADP+, so the diagram must distinguish the two correctly.
- Change “chemical energy” to “light energy” at the photosystem inputs — the photosystems absorb light energy to drive the reactions.

Do not switch PSII and PSI — the correct order in the light reactions is PSII first (P680) then PSI (P700).