| Comments |
"Perhaps the central issue in understanding the roles of Mg2+ in biological systems is the lack of suitable techniques and probes for determining its concentration
under various circumstances. Certainly atomic absorption spectrometry is accurate and sensitive in determination of the total mass of Mg2+
in a sample. However, the total amount of a substance is not, in general,
a very useful parameter. With many substances such as glucose or potassium, the total concentration approximates the ‘free’ or unbound concentration. It is this latter concentration that is thermodynamically relevant in determining the rate and extent of reactions. Unfortunately with Mg2+, techniques for measuring the free concentration of Mg2+ in biological systems are inadequate or nonexistent. The relative numbers of free and bound cations in a typical cell are illustrated in Table 2." See note underneath table |