Term
| describe the structure of porphyrins |
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Definition
| cyclic, 4 pyrole rings joined via methyl bridges with a N in the middle that binds to Fe |
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Term
| what is the most common porphyrin |
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Definition
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Term
| what is the job og prophyrin |
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Definition
| bind metal ions, usually Fe |
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Term
| what are examples of heme containing molecules |
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Definition
| Hb, myoglobin, cytochromes |
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Term
| what molecules do you need to begin synthesis of heme |
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Definition
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Term
| what enzyme turns glycine and succinyl CoA into aminoleyulinic acid (ALA) |
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Definition
| ALA synthase and vitamin B6 |
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Term
| what are the isoforms of ALA synthase |
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Definition
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Term
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Definition
| in the liver and other tissues |
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Term
|
Definition
| in RBC making tissues (like marrow) |
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Term
| what inhibits formation of ALAS1, how |
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Definition
| heme inhibits enzyme allosterically, decreases transcription, binds mRNA and degrades it |
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Term
| what regulates ALAS2, how |
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Definition
| Fe is required for heme synthesis so if there is Fe it stimulates the process but if there isnt' then it doesnt have the tools to do the job so heme synthesis wont work |
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Term
| what causes x linked cytoblastic anemia, what is it named with |
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Definition
| ALAS2 deficiency, because ALAS2 is on the X gene |
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Term
| what is x linked cytoblastic anemia |
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Definition
| immature RBC with nucleus overload with Fe and accumulate |
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Term
| what enzymes are effected by lead poisoning, causing anemia |
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Definition
| ALA dehydrogenase and ferrochetelase |
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Term
| where do ALA dehydrogenase and ferrochetelase appear in heme synthesis |
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Definition
| between ALA and the formation of heme |
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Term
| what is the rate limitng step in heme synthesis |
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Definition
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Term
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Definition
| deficiency in any other enzyme in heme synthesis |
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Term
| what causes the symptoms of porphyria |
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Definition
| defective enzyme causes intermediates to accumulate |
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Term
| what is the inheritance f porphyria |
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Definition
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Term
| what causes photosensitivity in porphyria |
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Definition
| oxidation of accumulated intermediades that are able to form ROS which can damage lysosomes releasing destructive enzymes |
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Term
| what are the symptoms of porphyria |
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Definition
| photosensitivity (itching, burning, blisters), neuropsychiatric disturbances, liver damage |
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Term
| what is the cause of acute porphyria |
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Definition
| induced by drugs metabolized by cytochrome P450 |
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Term
| porphyria causes a lack of heme, what effect does this ahve on the limit |
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Definition
| heme stops production of ALAS1, so without it production is increased and it further adds to the build up of intermediates |
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Term
| where does most heme that is degraded come from |
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Definition
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Term
| what is the first step in RBC turn over |
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Definition
| macrophages of liver and spleen take up old or damaged RBC and release bilirubin |
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Term
| what happens once bilirubin is made |
|
Definition
| it goes to the liver transported on albumin |
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Term
| what happens to bilitubin once it gets to the liver |
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Definition
| bilitubin glucuronyl transferase combines bilirubin and glucronate to make conjugated bilirubin |
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Term
| what happens to conjugated bilirubin |
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Definition
| it is sent out of the liver in bile and gut bacteria turns it into urobilinogen |
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Term
| what happens to nurobilinogen |
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Definition
| it is oxidized into sterocobilin or taken up by the liver |
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Term
| what happens to urobilinogen that is taken up by the liver |
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Definition
| it is sent out to bile or filtered to the kidney and turned into urobilin |
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Term
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Definition
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Term
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Definition
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Term
| what is the enterohepatic urobilinogen cycle |
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Definition
| urobilinogen is taken up by liver and sent out in the bile again |
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Term
| what is a mild genetic deficiency og bilirubin glucotransferase called |
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Definition
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Term
| what is a severe deficency of bilirubin glucotransferase called |
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Definition
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Term
| what does a deficiency og bilitubin glucotransferase cause |
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Definition
| unconjugated bilirubin build up which is toxic in nervous tissue |
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Term
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Definition
| bilirubin and its deravitives |
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Term
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Definition
| yellowing of skin, nail beds, sclerae |
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|
Term
| what are the types of jaundice |
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Definition
| hemolytic, hepatocellular, obstructive, newborn |
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Term
| what is hemolytic anemia caused by |
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Definition
| symptom of hemolytic anemia from diseases like sickle cell, thalacemia, G6PDH deficiency, etc |
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Term
| what occurs in hemolytic jaundice |
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Definition
| overwhelm liver's capacity to conjugate bilirubin causing it to build up |
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Term
| what occurs in hepatocellular jaundice |
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Definition
| liver damage leads to a defect in conjugation of bilirubin causing elevated levels in unconjugated bilirubin |
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Term
| what occurs in obstructive jaundice |
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Definition
| block in bile duct leads to accumulation of conjugated bilirubin in the liver releasing regurgitated conjugated bilirubin into the blood |
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Term
| what are the possible reasons for newbown jaundice |
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Definition
| fetus has too many RBC so they need to be turned over after birth, too little bilirubin glucornyl transferase to do conjugation |
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Term
| in general, what causes symptoms of newbown jaundice |
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Definition
| increased onconjugated bilirubin in the plasma |
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|
Term
| how is newbown jaundice treated |
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Definition
| blue florescent light, reacts with bilirubin making it more soluble so it can be filtered by kidney |
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