Question

In which portion of the chloroplast, pH is higher after ATP synthesis occurs through chemiosmosis in thylakoids?

• A. Stroma
• B. Lumen
• C. Space enclosed by the inner and outer membrane
• D. Space enclosed by the thylakoid membrane

Answer 1

The correct option is A Stroma

When the light hits the chloroplast, the chemiosmotic potential is established by thylakoid membrane. ATP is synthesised through chemiosmosis by transporting protons from the stroma to the lumen. Hence, the lumen becomes acidic compared to the stroma. Stoma will have higher pH compare to lumen.