This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Biochemistry
[{'content': 'Which amino acid migrates fastest on chromatography on carboxy methylcellulose medium? \nSelect and explain. \nA. Aspaic acid, B. Valine, C. Lysine, D. Glycine', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ai.e. Aspaic acidIn cation exchange chromatography solid stationary matrix has negatively charged groups (i.e. -ve charged carboxy methyl cellulose, 0 - CH2 - COO- is used as cation exchanger). So in the mobile phase, proteins with a net positive charge (i.e. cations) move slowly than those with net negative charge (anion)Q. Hence aspaate (aspaic acid) being a negatively charged amino acid will move fastest in carboxymethyl cellulose or methanol chloroform (cation exchanger) ion exchange chromatography.', 'role': 'assistant'}]