Questions: The ultimate source of energy for photosynthetic reactions in a plant is the sun. plants. glucose. glycogen catabolism The process that forms the electrochemical gradient during photosynthesis is the production of H+ in the stroma during NADPH production. movement of water by osmosis. hydrolysis of ATP. production of water from oxygen in the thylakoid lumen. pumping of H+ into the thylakoid lumen.

Question 7:
The answer is the first one: the sun.
Explanation:

• The sun: Correct. The ultimate source of energy for photosynthetic reactions in plants is sunlight. Plants capture solar energy through chlorophyll and use it to drive the process of photosynthesis.
• Plants: Incorrect. While plants perform photosynthesis, they are not the source of energy; they are the organisms that convert solar energy into chemical energy.
• Glucose: Incorrect. Glucose is a product of photosynthesis, not the source of energy.
• Glycogen: Incorrect. Glycogen is a storage form of glucose in animals, not related to the energy source for photosynthesis.
• Catabolism: Incorrect. Catabolism refers to the breakdown of molecules to release energy, not the source of energy for photosynthesis.

Question 8:
The answer is the last one: pumping of \(\mathrm{H}^{+}\) into the thylakoid lumen.
Explanation:

• Production of \(\mathrm{H}^{+}\) in the stroma during NADPH production: Incorrect. This does not directly form the electrochemical gradient.
• Movement of water by osmosis: Incorrect. Osmosis does not create the electrochemical gradient used in photosynthesis.
• Hydrolysis of ATP: Incorrect. ATP hydrolysis is a process that uses energy, not one that creates the electrochemical gradient.
• Production of water from oxygen in the thylakoid lumen: Incorrect. Water is split, not produced, in the thylakoid lumen during photosynthesis.
• Pumping of \(\mathrm{H}^{+}\) into the thylakoid lumen: Correct. This process creates the electrochemical gradient necessary for ATP synthesis during photosynthesis.

In summary, the ultimate source of energy for photosynthesis is the sun, and the electrochemical gradient is formed by the pumping of \(\mathrm{H}^{+}\) into the thylakoid lumen.