Catabolism of Heme

1. STUDY MATERIAL
ON
AMINO ACID METABOLISM
Presented By:
Ms. Sayali Dilip Powar
(M. Pharm )
Department of Pharmaceutical Chemistry,
@ Tatyasaheb Kore College of Pharmacy,
Warananagar
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2. General reactions of amino acid metabolism:
Transamination, deamination & decarboxylation, urea
cycle and its disorders
Catabolism of phenylalanine and tyrosine and their
metabolic disorders (Phenyketonuria, Albinism,
alkeptonuria, tyrosinemia)
Synthesis and significance of biological substances; 5-
HT, melatonin, dopamine, noradrenaline, adrenaline
Catabolism of heme; hyperbilirubinemia and jaundice
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3. Catabolism of heme
• Bilirubin is a bile pigment, and is the excretory
end product of heme degradation.

4. Catabolism of heme
• Hemoglobin  Heme
• Heme  Biliverdin by “Heme oxygenase”
• Biliverdin  Bilirubin by “Biliverdin reductase”
• Bilirubin  Bilirubin diglucuronide by “Bilirubin
glucuronyltransferase”
• Bilirubin diglucuronide  Urobilinogen by “Microbial
enzymes”
• Urobilinogen  Urobilin (To urine)
• Urobilinogen  Stercobilin (To feces)

5. BLOOD CELLS
Hemoglobin
Heme
INTESTINE AND KIDNEY
Urobilinogen
Urobilin
Excreted in Urine
Stercobilin
Excreted in Feces
Biliverdin
Bilirubin
LIVER
Bilirubin diglucuronide
Bilirubin

6. JAUNDICE
• Jaundice: Clinical condition characterized by
yellow colour of the white of the eyes (sclerae)
and skin. Caused by the deposition of bilirubin
due to its elevated levels in the serum, usually
beyond 2 mg/dl (normal < 1 mg/dl).
• Hyperbilirubinemia: The increased concentration
of serum bilirubin.

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8. • Bilirubin concentration range:
– Normal serum total bilirubin concentration: 0.2 to
1.0 mg/dl.
– Unconjugated: 0.2-0.6 mg/dl.
– Conjugated: 0.2 to 0.4 mg/dl.

9. 3 types of jaundice and major
changes
Hemolytic jaundice: Elevated serum unconjugated
bilirubin, and increased urinary excretion of
urobilinogen.
Obstructive jaundice: Elevated serum conjugated
bilirubin and increased activities of alkaline phosphatase
(ALP), alanine transaminase (ALT) and aspartate
transaminase (AST).
Hepatic jaundice: Elevated serum unconjugated and
conjugated bilirubin, and increased activities of ALT and
AST.