BIOMOLECULES AND ENZYMES

Detailed explanation-1: -Cystine is a dimer composed of two cysteine molecules linked via a disulfide bond. Cystine is much less soluble than cysteine and is responsible for cystine stone formation.

Detailed explanation-2: -Cysteine is transported into cells via neutral amino-acid transport systems, whereas cystine, the predominant form in plasma, extracellular body fluids and cell culture medium, is carried by the anionic amino-acid transport system, system xc− (Bannai and Tateishi, 1986).

Detailed explanation-3: -Cystine is the predominant form of cysteine extracellularly and a major form in which cysteine is acquired by tissues [11]. Alternatively, cysteine is produced from methionine through the de novo transsulfuration (TSS) pathway.

Detailed explanation-4: -Cystin. Cystine acid. Cysteine disulfide. (H-Cys-OH) 2-amino-3-[(2-amino-2-carboxyethyl)disulfanyl]propanoic acid.

Detailed explanation-5: -Cystine is the oxidized derivative of the amino acid cysteine and has the formula (SCH2CH(NH2)CO2H)2. It is a white solid that is poorly soluble in water.