Question

Z-scheme of electrons transfer involves

• A. Bundle sheath cells
• B. PS-I
• C. PS-II
• D. Both (B) and (C)

Answer 1

The correct option is D Both (B) and (C)

Z-scheme is a diagrammatic representation of the electron flow in non-cyclic phosphorylation, showing the change in energy potential of the electrons. The electrons lost by $P_{680}$ (PS-II) are taken up by $P_{700}$ (PS-I) and do not get back to $P_{680}$ i.e., unidirectional and hence, it is called non- cyclic phosphorylation. The electrons pass through the primary acceptor, plastoquinone (PQ), cytochrome complex, plastocyanin (PC) and finally to P700. The electrons given out by P700 are taken up by primary acceptor and are ultimately passed on to NADP. The electrons combine with H+ and reduce NADP to $NADP{H}_2$.