Thioliryhmät

Thioliryhmät, also known as sulfhydryl groups, are functional groups in organic chemistry with the general formula -SH. They consist of a sulfur atom bonded to a hydrogen atom. This group is analogous to the hydroxyl group (-OH) found in alcohols, with sulfur replacing oxygen. Thiols are sometimes referred to as mercaptans.

The sulfur atom in a thiol group is highly nucleophilic and can readily participate in various chemical reactions. A key characteristic of thiols is their ability to form disulfide bonds (-S-S-) through oxidation. This reaction is crucial in the structure and function of many biological molecules, such as proteins. For instance, the tertiary structure of proteins is often stabilized by disulfide bridges formed between cysteine residues.

Thiols are also known for their distinctive and often unpleasant odors, with low molecular weight thiols being particularly pungent. This property is utilized in the natural gas industry, where small amounts of thiols are added to odorless natural gas to make leaks detectable.

In biological systems, thiols play diverse roles. Besides their role in protein structure, they are involved in redox reactions, as antioxidants, and as components of coenzymes like Coenzyme A. The thiol group of cysteine is a key active site residue in many enzymes.

The chemical properties of thioliryhmät, including their acidity, nucleophilicity, and propensity for oxidation, make them important building blocks in organic synthesis and essential components in biological processes.