What is the significance of the proton gradient created during the light-depende
Practice Questions
Q1
What is the significance of the proton gradient created during the light-dependent reactions?
Drives ATP synthesis
Fixes carbon
Produces glucose
Generates oxygen
Questions & Step-by-Step Solutions
What is the significance of the proton gradient created during the light-dependent reactions?
Correct Answer: The proton gradient drives ATP synthesis through ATP synthase.
Step 1: During the light-dependent reactions of photosynthesis, light energy is absorbed by chlorophyll.
Step 2: This energy is used to split water molecules, releasing oxygen and creating protons (H+) and electrons.
Step 3: The electrons move through a series of proteins in the thylakoid membrane, which helps pump protons from the inside of the thylakoid space to the outside.
Step 4: This movement of protons creates a higher concentration of protons outside the thylakoid than inside, forming a proton gradient.
Step 5: The proton gradient represents stored energy, similar to water behind a dam.
Step 6: Protons flow back into the thylakoid space through a protein called ATP synthase.
Step 7: As protons flow through ATP synthase, it spins and helps convert ADP and inorganic phosphate into ATP.
Step 8: ATP is then used as energy for the next stage of photosynthesis, the light-independent reactions.
