Side chain polarity Reset Display the primary alcohol group as Ball & Stick. Ser differs structurally from Cys only in the oxygen for sulfur substitution. Some facts on L-serine. Abbreviation: Ser. One-letter code: S. Molecular mass: 105 daltons. Side chain (or R-group) features: Structural formula: Formula: -CH2-OH; Category: polar; neutral. pKa: none. Return to image of Ser.
Some facts on L-serine.