<prompt> Cysteine is formed fromMethionine and serineMethionine and glycineAlanine and glycineSerine and glycine  <response>: SerinHomocystein ---CysteineHomoserin.Homocystein is synthesized from Methionine.Ref: DM Vasudevan - Textbook of Biochemistry, 7th edition, page no: 217, Fig no 16.15 