Protoporphyrin IX
CH
HC
N
CH3
CH2
CH
=
N
CH3
CH
CH2
N
CH3
CH2
CH2
.
HOOC
N
CH3
CH2
COOH
CH2
.
H
C
H
C
This is formed in mitochondria by action
of
protoporhyrinogen oxidase on protoporhyrinogen IX which comes from coproporphyrinogen III