6.3.3.1 K+ absolutely required 6.3.3.1 K+ Km: 96 mM 6.3.3.1 K+ optimal concentration: 150 mM 6.3.3.1 Mg2+ optimal concentration: 20 mM 6.3.3.1 Mg2+ absolutely required 6.3.3.1 Mg2+ Km: 0.3 mM