A drum is a musical percussion instrument, consisting of a membrane which is usually stretched taut over a cylindrical tube that is open at the other end. The membrane is struck, either with the hand or some other object, and the tube forms a resonating chamber for the resulting sound. A drummer is a person who plays the drums.
... photophosphorylation
In cyclic electron flow, the electron originates in a pigment complex called photosystem I, passes from the primary acceptor to ferredoxin[?], ...