Question

In the light-dependent reaction of photosynthesis, light energy generates ATP. Describe how. (5)

a) By magic and fairy dust.
b) Light energy is converted into heat energy.
c) Light energy splits water into hydrogen and oxygen.
d) Light energy is used to pump protons into the thylakoid space, creating a proton gradient that drives ATP synthesis.

Answer 1

In the light-dependent reaction of photosynthesis, light energy is used to pump protons into the thylakoid space, creating a proton gradient that drives ATP synthesis. This is known as chemiosmosis.

Step-by-step explanation:

In the light-dependent reaction of photosynthesis, light energy is used to pump protons into the thylakoid space, creating a proton gradient that drives ATP synthesis. This process is known as chemiosmosis. Light energy is absorbed by pigment molecules in the photosynthetic membranes, such as chlorophyll, which initiates photosynthesis. The energy is then transferred to the electron transport chain, which pumps hydrogen ions into the thylakoid interior. These hydrogen ions flow through ATP synthase via chemiosmosis to create molecules of ATP, which are used for the formation of sugar molecules in the light-independent reactions.