Final answer:
FADP is not an electron carrier among the options provided; NAD, NADP, and FAD all function as coenzymes and shuttle electrons in various biochemical pathways.
Step-by-step explanation:
The question asks to identify which of the listed options is not an electron carrier. Electron carriers are molecules that shuttle high-energy electrons between different compounds in biochemical pathways. These carriers can be easily reduced or oxidized. Nicotinamide Adenine Dinucleotide (NAD), Nicotinamide Adenine Dinucleotide Phosphate (NADP), and Flavine Adenine Dinucleotide (FAD) are all known electron carriers. They are derived from the B vitamin group and function as coenzymes in many oxidation-reduction reactions. For example, NAD+ is the oxidized form and can accept electrons to become reduced to NADH, which includes an additional hydrogen ion and two more electrons. Similar processes happen with NADP and FAD. However, FADP is not a recognized electron carrier in biological systems and does not fit the naming convention or structure of known electron carriers.