Heme Metabolism Flashcards
(30 cards)
Heme is produced majorly in the ……….
Bone marrow
Liver
The heme synthesis is an how many step process
8 step process
Iron exist in hemoglobin in the ……… state
Ferrous ( reduced)
The types of heme are
Heme A in cytochrome A
Heme B in myoglobin ,hemoglobin and cyclooxygenase
Heme C in cytochrome C links via cysteine
Heme O.in bacterial oxidase
The most abundantly Heme is
Heme B
Where does tge last three steps of heme synthesis occur
Mitochondria
Where does tge last three steps of heme synthesis occur
Mitochondria
Heme synthesis is largely dependent on the availability of which iron
Fe2+
Deficiency of ALAS 2 in the synthesis of heme results in ……….
X-linked sideroblastic anaemia
The enzyme Aminolevulinic acid dehydratase is sensitive to ……….
pH and Mg 2+
Aminolevulinic acid is inhibited by heavy metals e.g
Lead
Deficiency of Aminolevulinic acid dehydratase leads to …………
Aminolevulinic acidic dehydratase deficiency porphyria
The linear tetra pyrrole formed during heme synthesis is ………
Hydroxymethylbilane
Enzyme involved in the synthesis of HMB is ………….
HMB synthase
PBG deaminase
Deficiency of PBG deaminase leads to
Intermittent porphyria
HMB is linked by ………… ring
Amine
HMB is converted to …….. by UROS
UPGIII synthase
The deficiency of UROS leads to…….
Congenital erythropoietic porphyria ( Autosomal recessive)
UPG III is converted to CPG III by what process
Decarboxylation of UPG III to CPG III
Acetate to methyl
And release of 4CO2 molecules
UROD deficiency leads to ……. porphyria
Familial porphyria cutanea tarda and
Hepatoerythropoietic porphyria
The enzyme responsible for conversion of CPG III to phorphobilinogen IX is
CPG III Oxidase
In the conversion of CPG III to Protoporphyrin IX what changes occur to the side chain
Decarboxylation of propionyl to vinyl
Reduced amount of CPG III oxidase leads to
Hereditary coproporphyria
PPGIX is converted to PPIX by ………. processs
Oxidation
