Which amino acid is the precursor for the synthesis of glutathione?

A Glutamic acid
B Cysteine
C Glycine
D All of the above
Glutathione is a tripeptide composed of glutamic acid, cysteine, and glycine, and all three amino acids are required for its synthesis.
Nelson et al., Lehninger Principles of Biochemistry
Protein Metabolism Biochemistry Amino Acid Metabolism Easy NURSING Confidence: high