This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Metabolism of Purines and Pyrimidines, Subject name: Biochemistry
[{'content': 'Porphyrins absorb light in the wavelength of: \nSelect and explain. \nA. 340 nm, B. 400 nm, C. 540 nm, D. 670 nm', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ref: Harper\'s Illustrated Biochemistry, 28th ed. Ch. 31. pp-272Explanation:"Porphyrins are strongly fluorescent: they absorb ultraviolet light (wavelength about 400 nm f nanometres), and re-emit it as a red light at about 630 nm. This property is used as the basis of most of our biochemical tests to detect porphyrins in urine, stool and blood."Porphyrias are a group of rare disorders caused by deficiencies of enzymes of the heme biosynthetic pathway. (See the following table) TypeEnzyme InvolvedMajor SymptomsLaboratory testsAcute intermittent porphyriaUroporphyrinogenlsvnchaseAbdominal pain NeurcpsvchiatricUrinary porphobilinogen |Congenitalerythropoietic porphyriaUroporphyrinogerc III cosynthasePhotosensitivityUrinary uroporphyrinPorphobilinogen|-Porphyria cutanea tardaUroporphyrinogenDecarboxylasePhotosensitivityUrinary uroporphyrinPorphobilinogen|-Variegate porphyriaProtoporphyrinogen OxidasePhotosensitivity Abdominal pain NeuropsychiatricUrinary uroporphyrinFecal coproporphyrinFecal protoporphyrin|||ErythropoieticprotoporphyriaFerrochelatasePhotosensitivityFecal protoporphyrinRed cell protoporphyrin||', 'role': 'assistant'}]