Previous-year question practice database
Answer
Exam answer
NICOTINAMIDE ADENINE DINUCLEOTIDE PHOSPHATE.
Explanation
Write every word out; the abbreviation earns nothing.
NADP is the HYDROGEN ACCEPTOR of the light reaction. When water is split by photolysis, the hydrogen released is picked up by NADP to form NADPH₂, which carries it into the dark reaction to reduce carbon dioxide to glucose.
It is the link between the two reactions — a carrier ferrying hydrogen from light to dark.
Watch the spelling: NICOTINAMIDE and DINUCLEOTIDE are where marks are lost.