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