ligand

(lĭg`ənd), charged or uncharged molecule with one or more unshared pairs of electrons that can attach to a central metallic atomatom
[Gr.,=uncuttable (indivisible)], basic unit of matter; more properly, the smallest unit of a chemical element having the properties of that element. Structure of the Atom
..... Click the link for more information. or ionion,
atom or group of atoms having a net electric charge. Positive and Negative Electric Charges

A neutral atom or group of atoms becomes an ion by gaining or losing one or more electrons or protons.
..... Click the link for more information. to form an aggregate known as a complex ion (see chemical bondchemical bond,
mechanism whereby atoms combine to form molecules. There is a chemical bond between two atoms or groups of atoms when the forces acting between them are strong enough to lead to the formation of an aggregate with sufficient stability to be regarded as an
..... Click the link for more information. ). Some ligands that share electrons with metals form very stable complexes. Some common bases that act as ligands are water and ammonia molecules and halide, hydroxide, acetate, cyanide, thiocyanate, and nitrite anionsanion
, atom or group of atoms carrying a negative charge. The charge results because there are more electrons than protons in the anion. Anions can be formed from nonmetals by reduction (see oxidation and reduction) or from neutral acids (see acids and bases) or polar compounds
..... Click the link for more information. . These ligands are monofunctional, i.e., they are attached by one unshared pair of electrons during complexing. Polyfunctional ligands, which bind to the metal ion with two or more pairs of electrons, are called chelates (see chelating agentschelating agents
. Certain organic compounds are capable of forming coordinate bonds (see chemical bond) with metals through two or more atoms of the organic compound; such organic compounds are called chelating agents.
..... Click the link for more information. ). Ethylenediamine-tetraacetate, a commonly used chelating compound, has six pairs of electrons to bind to metal ions. Electron-donating functional groups containing nitrogen, oxygen, sulfur, phosphorous, or carbon may act as ligands in complex biological systems. For example, in enzymes that need complexed metal ions to function, mercapto (sulfur-containing) groups and amino (nitrogen-containing) groups act as chelating agents; these groups fix the metal ion in a specific position. Other biologically important molecules, such as chlorophyll, vitamin B₁₂, and heme, also have nitrogen-containing groups that donate electrons and have a chelating function.

ligand

[′lī·gənd] (chemistry) The molecule, ion, or group bound to the central atom in a chelate or a coordination compound; an example is the ammonia molecules in [Co(NH₃)₆]³⁺.

ligand

[li´gand, lig´and] an organic molecule that donates the necessary electrons to form coordinate covalent bonds with metallic ions. Also, an ion or molecule that reacts to form a complex with another molecule.

lig·and

(lig'and, lī'gand), 1. Any individual atom, group, or molecule attached to a central metal ion by multiple coordinate bonds, for example, the porphyrin portion of heme, the corrin nucleus of the B12 vitamins. 2. An organic molecule attached to a tracer element, for example, a radioisotope. 3. A molecule that binds to a macromolecule, for example, a ligand binding to a receptor. 4. The analyte in competitive binding assays, such as radioimmunoassay. 5. An atom or group covalently attached to a specified carbon atom in an organic molecule. [L. ligo, to bind]

ligand

(lī′gənd, lĭg′ənd)n. An ion, molecule, or molecular group that binds to another chemical entity to form a larger complex.

li·gand

(lī'gand) 1. An organic molecule attached to a central metal ion by multiple coordinate bonds. 2. An organic molecule attached to a tracer element, e.g., a radioisotope. 3. A molecule that binds to a macromolecule, e.g., a ligand binding to a receptor. 4. The analyte in competitive binding assays, such as radioimmunoassay. [L. ligo, to bind]

ligand

A MOLECULE or ION that binds to a central chemical entity by non-covalent bonds. A general term for any molecule that is recognized by a surface receptor.

ligand

a molecule able to bind to a specific ANTIBODY and used to distinguish closely similar types of antibody.

li·gand

(lī'gand) 1. Any individual atom, group, or molecule attached to a central metal ion by multiple coordinate bonds. 2. An organic molecule attached to a tracer element. 3. A molecule that binds to a macromolecule. [L. ligo, to bind]

ligand

li·gand

ligand

li•gand

ligand

ligand

ligand

ligand

ligand

lig·and

ligand

li·gand

ligand

ligand

li·gand

ligand

Words related to ligand

noun a substance (an atom or molecule or radical or ion) that forms a complex around a central atom

Related Words