Porphyrins absorb light in the wavelength of:: (A) 340 nm, (B) 400 nm, (C) 540 nm, (D) 670 nm
Answer is B. 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||