BioInteractive Light Reactions of Photosynthesis 1 — Questions and Answers
Question 1: Where do the light reactions of photosynthesis take place?
- Thylakoid membranes (Correct answer)
- Stroma
- Cytoplasm
- Mitochondria
Correct answer: Thylakoid membranes
The light reactions occur on the thylakoid membranes inside the chloroplast.
Question 2: Which molecule captures light energy during the light reactions?
- Chlorophyll (Correct answer)
- ATP
- NADPH
- RuBisCO
Correct answer: Chlorophyll
Chlorophyll absorbs light energy and initiates the light-dependent reactions.
Question 3: What are the two main products of the light reactions used in the Calvin cycle?
- ATP and NADPH (Correct answer)
- CO2 and H2O
- Glucose and O2
- ADP and NADP+
Correct answer: ATP and NADPH
The light reactions produce ATP and NADPH, which power the Calvin cycle.
Question 4: What is the source of electrons that replace those lost by Photosystem II?
- Water (Correct answer)
- NADPH
- CO2
- Glucose
Correct answer: Water
Water molecules are split (photolysis) to donate electrons to Photosystem II.
Question 5: What is the oxygen released during photosynthesis derived from?
- Water (Correct answer)
- Carbon dioxide
- Glucose
- ATP
Correct answer: Water
Oxygen is released when water is split during the light reactions at Photosystem II.
Question 6: Which photosystem absorbs light at 700 nm and is involved in producing NADPH?
- Photosystem I (Correct answer)
- Photosystem II
- Both equally
- Neither
Correct answer: Photosystem I
Photosystem I (P700) absorbs 700 nm light and passes electrons to NADP+ reductase to form NADPH.
BioInteractive Light Reactions of Photosynthesis 1
Where do the light reactions of photosynthesis take place?