Question

The light reactions of photosynthesis use chemiosmosis to produce ATP that will be used in the Calvin cycle. The electrochemical gradient that drives this chemiosmosis is formed across which structure(s)?

-Stroma
-Stomata
-Thylakoid membrane
-Cristae
-Outer membrane of the chloroplast
-Photosystem II

Answer 1

The electrochemical gradient for chemiosmosis in the light reactions of photosynthesis is established across the thylakoid membrane, and is essential for ATP production used in the Calvin cycle.

Step-by-step explanation:

The electrochemical gradient that drives chemiosmosis in the light reactions of photosynthesis is formed across the thylakoid membrane. The light-dependent reactions of photosynthesis utilize the energy from sunlight to transfer electrons from water to NADP+, producing NADPH. In the process, protons are moved across the thylakoid membrane into the thylakoid lumen, creating a high concentration of hydrogen ions there. This gradient is then used by ATP synthase to produce ATP, which is utilized in the Calvin cycle to convert CO₂ into organic compounds.