Heme degradation and Jaundice -1

Production of Heme occurs in Reticuloendothelial system ( RES)
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Terms in this set (16)
Production of Heme occurs in Reticuloendothelial system ( RES)
True. RES consist of macrophages , Macrophage precursors in liver, spleen , Bone marrow, Lymphatic system and fibroblasts.
Heme oxygenase is the only CO producing enzyme in human body
True.
After a punch on face leaves a black eye, color transitions from Blue--> green--> yellow---> normal. Explain the transition of color
After a punch on face--> capillaries are ruptures--> RBC are stranded in interstitial space --> their HB becomes deoxygenated ( Blue)--> Erythrocytes are eaten by macrophages after a few days-->Heme is degraded to biliverdin( green)-- bilirubin ( yellow)--> Bilirubin leaves the place to travel to liver ( normal color of skin)
Unconjugated bilirubin ( UCB) is water soluble
False, UCB is water insoluble/lipid soluble
Heme oxygenase is NADP dependent enzymes and is present in ER of cells of reticuloendothelial system
True
Since Unconjugated bilirubin is water insoluble, it travels in blood bound to albumin
True, Binding of unconjugated bilirubin to albumin increases the solubility of bilirubin in blood and helps in transport of bilirubin to liver for excretion from body
Albumin has high affinity and low affinity sites for binding to bilirubin?
True.
At higher bilirubin concentrations, ( > 25 mg/dl) , bilirubin binds to low affinity sites on albumin
True. When bilirubin binds to albumin, first high affinity sites are occupied , later as the concentration of bilirubin increases low affinity sites are occupied.
Kernicterus is deposition of bilirubin in brain and can result in Mental retardation
True. When unconjugated bilirubin concentration is higher, it binds to low affinity site on albumin. Theses sites bind bilirubin loosely and can release bilirubin in circulation. The unconjugated bilirubin diffuses into tissues and gets deposited ( as it is lipid soluble)
Conjugation of bilirubin with glucuronic acid occurs in liver and makes it water soluble .
True. Conjugation of bilirubin with glucuronic acid occurs on ER of hepatocytes and converts it into conjugated bilirubin which is water soluble. The reaction is catalyzed by UDP glucuronsyl transferase. UDP1A1.
Unconjugated bilirubin binds to albumin through covalent bondsFalse. There are two types of binding sites on albumin- High affinity sites ( which bind bilirubin noncovalently and tightly) Low affinity sites ( which bind bilirubin non covalently and loosely)Bilirubin monoglucuronide and Bilirubin diglucuronide are water soluble forms of bilirubin.True. These are two forms of conjugated bilirubin which is water soluble.Secretion of conjugated bilirubin into bile is an active process- mediated by ATP dependent transporter MRP2.True. MRP2 also known as multidrug resistant protein & is member of MOAT ( Multiple organic anion transporter)Urobilinogen is reduced to sterobilinogen by gut bacteria which forms stercobilin. The stercobilin is responsible for color of stoolTrueUrobilin is responsibile for color of urineTrueFate of urobilinogen in intestine - explainMost of urobilinogen ( UBG) is reduced to stercobilinogen which is excreted in feces, Some of it enters enterohepatic circulation and is reexcreted in bile. A small amount of UBG reaches kidneys and is excreted in urine either as such or after oxidation to yellow urobilin which is responsible for yellow color of urine.