Final answer:
Mg2+ can act as a cofactor for enzymes, stabilizing their structure and enhancing their function, crucial for the active enzyme complex known as a holoenzyme.
Step-by-step explanation:
Yes, Mg2+ can act as a cofactor, which is a type of non-protein helper molecule that binds to enzymes. This binding is essential for the formation of a holoenzyme, which is the active form of an enzyme complex. When a cofactor such as Mg2+ binds to an apoenzyme (the protein component of an enzyme), it helps to stabilize the enzyme's structure and enhance its function.
Cofactors are inorganic ions, while coenzymes, another type of helper molecule, are organic and are often derived from vitamins. For example, magnesium ions (Mg2+) are crucial for the activity of numerous enzymes, including the pyruvate dehydrogenase complex, which requires both a magnesium ion and multiple coenzymes to function correctly.