Aspartic acid is a non-essential amino acid that plays a critical role in the citric acid cycle and as a neurotransmitter in the central nervous system. It exists in L- and D-forms, with the L-isomer being the biologically active form incorporated into proteins. It is involved in the biosynthesis of other amino acids, nucleotides, and in ammonia detoxification via the urea cycle. Industrially, it is used in sweeteners like aspartame and as a food additive. It has two carboxylic acid groups and one amino group, making it acidic with an isoelectric point around 2.8. Solubility in water is limited at approximately 4.5 g/L at 25°C.