Question

Which of the following happens during the light-dependent phase of photosynthesis?

A) Water molecules are split, forming oxygen and free electrons.
B) ATP synthase makes ATP from ADP.
C) Energized electrons pass through the electron transport chain.
D) All of these

Answer 1

The light-dependent phase of photosynthesis involves the splitting of water molecules to release oxygen and electrons, the transfer of energized electrons through the electron transport chain, and the generation of ATP using ATP synthase, as well as the production of NADPH.

Step-by-step explanation:

During the light-dependent phase of photosynthesis, the following events occur:

• Water molecules are split, releasing oxygen and providing free electrons. This process is facilitated by the energy absorbed from sunlight by chlorophyll molecules in the photosystem complexes.
• The free electrons gained from water are excited further by the sunlight absorbed in the photosystems and are passed along the electron transport chain, creating a gradient that enables the production of ATP.
• Using the enzyme ATP synthase, ATP is generated from ADP and inorganic phosphate. This enzymatic activity is driven by the flow of protons across the thylakoid membrane, a process called chemiosmosis.
• NADPH is produced when the excited electrons reach the end of the electron transport chain and are transferred to NADP+.

So, the correct answer is D) All of these events occur during the light-dependent phase of photosynthesis.