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57 Cards in this Set
- Front
- Back
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What are Porphyrins?
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-Cyclic Compounds
-Readily bind Metal Ions |
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Describe the Structure of Porphyrins.
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-Cyclic Compounds
-4 Pyrrole Rings -Side Chains |
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What are Reduced Porphyrins called?
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Porphyrinogens
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What are Porphyrinogens?
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Reduced Porphyrins
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What molecule is a Iron Protoporphyrin?
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Heme
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Where does Biosynthesis of Heme Occur? Using What?
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-Liver - Cytochrome p450 (Monooxygenase)
-Bone Marrow - Hemoglobin (Transport Oxygen) |
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In which Organelle is Heme formed?
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Mitochondria
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What is the 1st Step in Heme Synthesis? Where does it Occur? What is it catalyzed by?
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-Glycine + Succinyl CoA = ALA (Delta-Aminolevulinic Acid)
-Mitochondria -ALA Synthase |
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What does ALA Synthase do? What is important about this reaction?
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-Catalyzes the Formation of ALA (Delta-Aminolevulinic Acid) from Glycine and Succinyl CoA
-1st Step in Heme Formation |
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What does Hemin do? How?
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-Inhibits the action of ALA Synthase
-Oxidzes Fe2+ to Fe3+, which can't be used in Heme |
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What substance inhibits the activity of ALA Synthase by Oxidizing Fe2+ to Fe3+?
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Hemin
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What drug Increases ALA Synthase Activity? How does it do?
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-Phenobarbital
-Cytochrome P450 Monooxygenase System is Induced to Metabolize Drugs which Results in More Heme to be Used |
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What are Prophyrias?
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Defects in Heme Synthesis
-Usually Congenital -Result in Accumulation of Porphyrins or Porphyrin Precursors |
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What are some symptoms of Porphyrias?
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-Photosensitivity - Due to Superoxide Radicals
-Damage to Membranes - Release of Enzymes from Lysosomes -Increased ALA Synthase Activity |
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Why is ALA Synthase Activity Increased in Porphyrias?
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-Heme Deficiency and Increase in Intermediates
-Heme Normally Inhibits ALA Synthase Activity -Without Heme, we get Further Accumulation of Intermediates |
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What are the 2 Types of Porphyrias?
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-Erythropoetic Porphyrias
-Hepatic Porphyrias |
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How are Porphyrias treated? Why?
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-Hemin - Inhibit ALA Synthase
-Avoidance of Sunlight -Ingestion of Antioxidants |
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What is the Most Common Porphyria? How does it result?
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Porphyria Cutanea Tarda
Most Common Porphyria -Deficiency in Uroporphyrinogen -Decarboxyase |
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WTF is going on in Porphyria Cutanea Tarda?
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-Deficiency of Uroporphyrinogen Decarboxyase
-Uroporphyrin Accumulates in the Urine |
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What is the major source for Catabolism of Heme?
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Senescent RBCs
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What breaks down Heme to Bilirubin?
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Macrophages
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What role do Macrophages play in the Catabolism of Heme?
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Breakdown Heme to Bilirubin
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How is Unconjugated Bilirubin Transported? Where is transported to?
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-Bound to Albumin
-To the Liver |
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What happens to Bilirubin once it reaches the Liver? What results?
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-Conjugated with Glucuronic Acid
-Bilirubin Diglucuronide |
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What form of Bilirubin is Excreted in the Urine? Feces?
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-Urobilin
-Stercobilin |
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What form of Bilirubin makes it to the Portal Blood? Excreted in the Urine? Where is it converted?
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-Urobilinogen
-Urobilin -Kidney |
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What causes Jaundice (in general)?
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Increased Levels of Bilirubin in the body
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What is Hemolytic Jaundice? What is it caused by?
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-Mass Lysis of RBCs
-Sickle-Cell Anemia, Pyruvate Kinase, G6PD Deficiency |
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How does Jaundice result in the case of Hemolytic Jaundice?
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-Mass Lysis of RBCs
-Urobilinogen in the Enterohepatic Circulation and Urine Increases -Unconjugated Bilirubin Levels Increase and can't remove fast enough |
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What form of Bilirubin enters the Enterohepatic Circulation
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Urobilinogen
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How does Jaundice result in the case of Hemolytic Jaundice (General)?
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-Increased Hemolysis
-Increased Unconjugated Bilirubin -Hemolytic Jaundice |
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What is Obstructive Jaundice? What usually causes it?
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-Jaundice due to Obstruction of the Bile Duct
-Hepatic Tumor or Bile Stones |
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Why is Obstructive Jaundice a problem? What results?
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-Obstruction in the Bile Duct
-Bilirubin is passed into Blood rather than SI -GI Pain, Nausea, Pale Clay Stools |
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How does Jaundice result in the case of Obstructive Jaundice (General)?
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-Decreased Excretion of Bilirubin
-Increased Bilirubin the Blood -Obstructive Jaundice |
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What is Hepatocellular Jaundice? What can cause it?
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-Due to a Deficiency of Conjugation of Bilirubin
-Liver Damage - Cirrhosis or Hepatitis |
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How does Hepatocellular Jaundice cause Jaundice (in general)?
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-Decreased Conjugation
-Increased Unconjugated Bilirubin -Hepatocellular Jaundice |
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What happens in Hepatocellular Jaundice?
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-Conjugated Bilirubin Diffuses into the Blood but not into the Bile
-Urobilinogen is Increased in the Urine -Results in Dark Urine and Play Clay Stools |
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Which NTs are Catecholamines?
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-DA
-E -NE |
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What do DA and E do?
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-NTs
-Relay, Amplify, and Modulate signals between neurons |
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Which Catceholamines are released in outside the CNS in fight or flight?
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E and NE
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Pathway of Catecholamine Synthesis.
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Tyrosine > DOPA > DA > NE > E
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What catalyzes the formation of DOPA from Tyrosine?
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Tyrosine Hydroxylase
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What is the rate-limiting step in Catecholamine Synthesis?
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Tyrosine > DOPA
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What converts NE to E?
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SAM
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What role does SAM play in Catecholamine Synthesis?
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Converts NE to E
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Which enzymes degrade Catecholamines?
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-MAO
-COMT |
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What do many Anti-depressants Target? Why?
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-MAO Inhibitors
-Allow Accumulation of Catecholamines in Presynaptic Neuron |
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What is so cool about Creatine?
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-It is a Storage of High Energy Phosphate in Tissues
-Particularly Cardiac and Skeletal Muscle |
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How is Creatine stored in Muscle?
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As Creatine Phosphate
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How does Creatine Help regenerate ATP in Muscle?
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-Creatine Phosphate is the storage form
-Converted to Creatine to generate ATP from ADP |
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What is Creatinine?
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Breakdown product of Creatine
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What can Creatinine Levels be an estimator for?
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-Muscle Mass
-Potential Kidney Malfuction -Paralysis or Muscular Dystrophy |
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What is the amount of Creatinine Excreted Proportional to?
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Total Creatine Phosphate
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What's so fucking great about Histamine?
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-Powerful Vasodilator
-Secreted due to Allergic Reactions or Trauma by Mast Cells |
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What is Serotonin Synthesized from?
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Tryptophan
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Where is 90% of Serotonin found?
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GI Tract
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What are the Effects of 5HT (Serotonin)?
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-Increased Pain Perception
-Affective Disorders -Regulation of Sleep, Temperature, and Blood Pressure |
