Low magnesium disrupts many enzyme systems. Which type of enzyme-dependent process is most likely to be impaired by low intracellular magnesium?

• A. ATP-dependent kinases and other enzymes that require Mg2+ as a cofactor to stabilize ATP and facilitate phosphoryl transfer.
• B. The polymerization of DNA into chromosomes during mitosis, because magnesium is the main structural component of chromatin compaction and histone assembly.
• C. Vitamin C biosynthesis in humans, since humans synthesize vitamin C in large quantities and require magnesium directly for the hydroxylation steps of its production.
• D. Lipase-mediated fat digestion in the intestinal lumen that depends exclusively on free fatty acids and bile salts without requiring metal cofactors.

Answer: (A)