Figure 1.

Chemistry of Ca²⁺ binding to buffers. A, Schematics showing Ca²⁺ in various environments: water (i), bound to EDTA (ii), and bound to an EF hand (iii). B, Reaction schemes for Ca²⁺ binding to various buffers: simple binding (i), competition with Mg²⁺ (ii), and competition with protons (iii).