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Enzymes with a zinc atom in the reactive center are widespread in biochemistry, such as alcohol dehydrogenase in humans. [17] Consumption of excess zinc may cause ataxia, lethargy, and copper deficiency. In marine biomes, notably within polar regions, a deficit of zinc can compromise the vitality of primary algal communities, potentially ...
It adopts a polymeric structure consisting of tetrahedral zinc centres linked by bridging cyanide ligands. The cyanide group shows head to tail disorder with any zinc atom having between 1 and 4 carbon atom neighbours and the remaining being nitrogen atoms. These two examples illustrate the difficulty of sometimes relating structure to ...
Zinc fingers form parts of some transcription factors, which are proteins that recognize DNA base sequences during the replication and transcription of DNA. Each of the nine or ten Zn 2+ ions in a zinc finger helps maintain the finger's structure by coordinately binding to four amino acids in the transcription factor. [25]
Naturally occurring zinc (30 Zn) is composed of the 5 stable isotopes 64 Zn, 66 Zn, 67 Zn, 68 Zn, and 70 Zn with 64 Zn being the most abundant (48.6% natural abundance).Twenty-eight radioisotopes have been characterised with the most stable being 65 Zn with a half-life of 244.26 days, and then 72 Zn with a half-life of 46.5 hours.
A zinc finger is a small protein structural motif that is characterized by the coordination of one or more zinc ions (Zn 2+) which stabilizes the fold. The term zinc finger was originally coined to describe the finger-like appearance of a hypothesized structure from the African clawed frog (Xenopus laevis) transcription factor IIIA.
For instance, zinc and cadmium are similar to beryllium and magnesium in their atomic radii, ionic radii, electronegativities, and also in the structure of their binary compounds and their ability to form complex ions with many nitrogen and oxygen ligands, such as complex hydrides and amines.
Each atom is tetrahedrally coordinated. The structure can also be described as an HCP lattice of zinc with sulfur atoms occupying half of the tetrahedral voids or vice versa. The wurtzite structure is non-centrosymmetric (i.e., lacks inversion symmetry).
However, it differs from rock-salt structure in how the two lattices are positioned relative to one another. The zincblende structure has tetrahedral coordination: Each atom's nearest neighbors consist of four atoms of the opposite type, positioned like the four vertices of a regular tetrahedron. In zinc sulfide the ratio of zinc to sulfur is 1 ...