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 of the following does not undergo phosphorylation by protein kinases in Eukaryotes: \nSelect and explain. \nA. Threonine, B. Tyrosine, C. Serine, D. Asparagine', 'role': 'user'}, {'content': 'Answer: D \nExplanation: D i.e. AsparagineSerine, threonine and tyrosine undergo phosphorylation by protein kinase (in eukryotes) during post translational modifications- Extra carboxyl group is added to glutamate residue of blood clotting protein prothrombin (carboxylation). Lysine undergo methylation in some muscle proteins (mono & dimethyllysine), and calmodulin (trimethyl lysine); carboxy group of glutamate undergo methylation removing their negative charge.', 'role': 'assistant'}]