role ▁ring ▁( adj acent ▁to ▁the ▁nit ro gen ▁atom ) ▁into ▁hydro x ym eth yl ▁bil ane ▁by ▁the ▁en zym e ▁por ph obil in ogen ▁de amin ase , ▁also ▁known ▁as ▁hydro x ym eth yl bil ane ▁synth ase . ▁ ▁Path ologies ▁Ac ute ▁inter mitt ent ▁por phy ria ▁causes ▁an ▁increase ▁in ▁ur inary ▁por ph obil in ogen . ▁ ▁References ▁▁ ▁Category : Met abol ism ▁Category : P yr ro les ▁Category : Car box y lic ▁ac ids ▁Category : A min es <0x0A> </s> ▁Ar p ▁ 2 7 2 ▁is ▁a ▁pair ▁of ▁interact ing ▁galaxies ▁consisting ▁of ▁the ▁two ▁spir al ▁galaxies ▁NGC ▁ 6 0 5 0 ▁( left ) ▁and ▁IC ▁ 1 1 7 9 ▁( right ). ▁Ar p ▁ 2 7 2 ▁lies ▁around ▁ 4 5 0 ▁million ▁light ▁years ▁from ▁Earth ▁in ▁the ▁const ell ation ▁of ▁Her cules . ▁The ▁galaxies ▁are ▁part ▁of ▁the ▁Her cules ▁Cl uster , ▁which ▁is ▁itself ▁part ▁of ▁the ▁C f A 2 ▁Great ▁Wall . ▁ ▁The ▁two ▁galaxies ▁in ▁Ar p ▁ 2 7 2 ▁are ▁in ▁physical ▁contact ▁through ▁their ▁spir al ▁arms . ▁A ▁third ▁galax y ▁can ▁be ▁seen ▁at ▁the ▁top ▁of ▁them ; ▁that ▁galax y ▁is ▁also ▁interact ing ▁with ▁them . ▁ ▁References ▁ ▁External ▁links ▁▁▁▁ 2 7 2 ▁Category : Inter act ing ▁galaxies ▁Category : N GC ▁objects ▁Category