Search results
Results From The WOW.Com Content Network
Zinc fingers help read DNA sequences.. Zinc is an essential trace element for humans [1] [2] [3] and other animals, [4] for plants [5] and for microorganisms. [6] Zinc is required for the function of over 300 enzymes and 1000 transcription factors, [3] and is stored and transferred in metallothioneins.
For example, terpyridine, which is a tridentate ligand forms the complex [Zn(terpy)Cl 2]. Another example would involve a tripodal ligand such as Tris(2-aminoethyl)amine. Square pyramidal 5-coordinate Zinc is found in Tetra(4-pyridyl)porphinatomonopyridinezinc(II) [ 19 ] Solution studies of other 5-coordinate Zinc porphyrins have been reported.
Number of consonants denotes number of oxygen atoms. Number of vowels denotes negative charge quantity. Inclusion of the word "ate" signifies that each ends with the letters a-t-e. To use this for the -ite ions, simply subtract one oxygen but keep the charge the same.
Zinc is a chemical element with the symbol Zn and atomic number 30. It is a slightly brittle metal at room temperature and has a shiny-greyish appearance when oxidation is removed. It is the first element in group 12 (IIB) of the periodic table .
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 .
The formal oxidation state of the oxygen atoms is − 1 ⁄ 2. In solutions at neutral pH, the superoxide ion disproportionates to molecular oxygen and hydrogen peroxide. 2 O − 2 + 2 H + → O 2 + H 2 O 2. In biology this type of reaction is called a dismutation reaction. It involves both oxidation and reduction of superoxide ions.
This dualism is an example of polymorphism. In each form, the coordination geometry at Zn and S is tetrahedral. The more stable cubic form is known also as zinc blende or sphalerite. The hexagonal form is known as the mineral wurtzite, although it also can be produced synthetically. [2]
Metallothioneins are rich in thiols, causing them to bind a number of trace metals. Metallothionein is one of the few eukaryotic proteins playing a substantial role in metal detoxification. Zinc and Cadmium are tetrahedrally coordinated to cysteine residues, and each metallothionein protein molecule may bind up to 7 atoms of Zn or Cd. [5]