L-serine is the L-enantiomer of serine. It has a role as a human metabolite, an algal metabolite, a Saccharomyces cerevisiae metabolite, an Escherichia coli metabolite and a mouse metabolite. It is a serine family amino acid, a proteinogenic amino acid, a L-alpha-amino acid and a serine. It is a conjugate base of a L-serinium. It is a conjugate acid of a L-serinate. It is an enantiomer of a D-serine. It is a tautomer of a L-serine zwitterion.