The first step in photosynthesis is

$ATP$ synthesis in chloroplasts and mitochondria is due to a proton gradient across the membrane. Select the correct statements with respect to $ATP$ formation in chloroplasts:
$(a)$ Protons accumulate in the lumen of the thylakoid.
$(b)$ Splitting of water occurs on the inner side of the membrane.
$(c)$ Protons accumulate on the stroma side of the chloroplast.
$(d)$ $NADP$ reductase is located on the stroma side of the membrane.

$(a)$ $NADP$ reductase enzyme is located on $.....$
$(b)$ Breakdown of proton gradient leads to release of $.........$

Which pigment acts as the reaction center during photosynthesis?

Ferredoxin is a component of

Photophosphorylation is the synthesis of ..........