Cysteinaminosyre

Cysteinaminosyre, also known as cysteine, is a semi-essential proteinogenic amino acid with the formula HSCH2CH(NH2)COOH. Its side chain contains a thiol group, which is responsible for its unique chemical properties. Cysteine is one of only two proteinogenic amino acids that contain sulfur, the other being methionine.

The thiol group in cysteine is highly reactive and can form disulfide bonds (S-S) with other cysteine residues. This disulfide bond formation is crucial for the three-dimensional structure and stability of many proteins, including enzymes and structural proteins. It plays a vital role in protein folding and the maintenance of protein integrity.

In the human body, cysteine is synthesized from methionine, another sulfur-containing amino acid. While the body can produce cysteine, adequate dietary intake is still important, especially under certain physiological conditions like rapid growth or illness. It is found in many protein-rich foods such as meat, dairy, eggs, and legumes.

Cysteine serves as a precursor for several important biomolecules. It is involved in the synthesis of glutathione, a powerful antioxidant that protects cells from oxidative damage. It is also a component of keratin, a structural protein found in hair, skin, and nails. Furthermore, cysteine plays a role in the metabolism of various compounds and in detoxification processes.