porphoryins and hemoglobin

Question 1

thalessemias

Answer 1

defects in synthesis of alpha or beta chains

Question 2

hemoglobulinpathy: sickel cell anemia

Answer 2

homozygous for hemoglobin S

point mutation resulting in substitution of valine for glutamate in beta units

Question 3

glucosylation of hemoglobin occurs in ?

Answer 3

diabtete mellitus

Question 4

carbon monoxide competes with oxygen for ?

Answer 4

binding the heme iron

Question 5

oxygen transport mediated by what 2 heme proteins?

Answer 5

myoglobin - occurs in muscle/single polypeptide chain
O2 curve is hyperbola
hemoglobin - occurs in red blood cells/ 4 polypeptide chains
O2 curve is sigmoidal

Question 6

binding of O2 is decreased by decrease in pH (bohr effect) and by an increase in?

Answer 6

2,3-

bisphosphoglycerate

Question 7

porphyria cutanea tarda

Answer 7

defieciency in uroprophrynigen decarboxylase

uroporphyrin accumulates in urine

Question 8

acute intermittent porphyria

Answer 8

deficiency in hydroxymethylbilane synthase
ALA and porphobilogen accumulate in urine
urine darkens exposed to light and air
only here patients are NOT photosensitive

Question 9

Types of jaundice?

Answer 9

prehapatic jaundice - hemolytic jaundice
hepatic jaundice - problems in liver
post hepatic jaundice - obstruction in bile duct

Question 10

degradation of heme

Answer 10

break down and oxidation of heme in macrophage gives biliverdin and iron
iron is recycled and biliverdin reduced to bilirubin
bilirubin goes to liver and reacts with glucuronic acid
bilirubin converted to bile and excreted

Question 11

jaundice

Answer 11

elevation of serum bilirubin level above normal level of 1 mg/dl

Question 12

hemolytic anemia

Answer 12

hemoglobinemia frequently conjugated by hyperbilirubinemia. rate of heme degradation exceeds max rate of bilirubin removal from liver

Question 13

regulation of hemoglobin synthesis involves control of?

Answer 13

porphyrin and polypeptide synthesis
heme oxidized to hemin
hemin decreases activity of delta aminovulinate which can shut off porphyrin synthesis
hemin can activate synthesis of globin peptide to keep synthesis of heme and globin in balance

Question 14

porphoryn synthesis: formation of heme

Answer 14

1. glycine + succinyl coA catalyzed by d-aminolevulinate synthase makes d -aminolevulinate (ALA)
   d -aminolevulinate synthase is inhibited by heavy metal ions
2. d -aminolevulinate condense to form the monopyrrole, porphobilinogen (4 molecules condense)
3. then you get hydroxymethylbilane (ring closure and isomerization)
   4.uroporphyrinogen III
   5.The conversion of intermediate protoporphyrin IX to heme is catalyzed by ferrochelatase

Question 15

porphyria

Answer 15

too much porphyrin may mean you have a type of porphyria that prevent your body from correctly making heme

Question 16

porphyrin

Answer 16

Porphyrins are chemicals that help make hemoglobin, a type of protein in your red blood cells. heterocyclic ring structure with 4 pyrole rings
functions in 
O2 transport
breaksdown peroxide
electron transport
light absorption