_____ releases energy that is used to pump hydrogen ions from the stroma into the thylakoid compartment.
The figure shows the membrane of the thylakoid. Letters from A to E indicate definite structures. Letter A indicates the first protein complex of the light-dependent reactions, which is located in the thylakoid membrane. Letter B indicates the multiprotein complex between two photosystems. Letter C marks the second integral membrane protein complex of the light-dependent reactions. Letter D marks the substance inside thylakoid. Letter E indicates the flask-shaped structure, which has a canal for hydrogen ions.
A. D
B. A
C. B
D. C
E. E
Explanation: first protein complex of the light-dependent reactions, which is located in the thylakoid membrane, and the electron transport chain is also a factor in it but it doesn't mention that.
