Which chemical compound is the primary constituent of human bones and teeth, making up more than 50% of their mass?

Who first used phenyl isothiocyanate (PITC) for the sequential N-terminal degradation and sequencing of peptides?

In the vitamin K cycle, the conversion of vitamin K quinone to vitamin K hydroquinone is catalyzed by which enzyme?

Which of the following natural food pigments is most stable to thermal and pH variations?