Zn2Ion

Zn2+ ion, or zinc(II) ion, is the divalent cation of zinc with a charge of +2. In aqueous solution it is typically represented as the hexaaquazinc(II) complex [Zn(H2O)6]2+. Zinc(II) can form various hydrolysis species depending on pH, evolving toward zinc hydroxide Zn(OH)2 at higher pH. In solids and coordination compounds, zinc commonly adopts coordination numbers of four or six, binding ligands such as water, hydroxide, and amino acid residues.

Zn2+ is essential for many biological processes. It acts as a catalytic cofactor for a broad range of enzymes, including carbonic anhydrase, alkaline phosphatase, and various metalloproteases, and it serves a structural role in zinc finger domains that stabilize protein folds and DNA binding. Within cells, zinc homeostasis is tightly regulated by transport proteins of the ZIP and ZnT families and by metallothioneins that store or detoxify zinc. The ion also participates in signaling, transcriptional regulation, and immune function.

Humans obtain zinc as a trace element essential for growth, development, and immunity. Deficiency can lead to growth retardation, skin and wound-healing problems, and increased susceptibility to infection, while excess zinc can be toxic and interfere with copper absorption. Dietary sources include meat, seafood, dairy, legumes, and fortified foods. Zinc compounds and salts are used in supplements and agriculture, and zinc occurs naturally in minerals such as sphalerite.