Heme Biochemistry Flashcards
What is the inheritance pattern of sideriblastic anemia
X-linked
How does protoporphyrin production match to iron availability ?
ALAS2 has IRE
How do we manage acute attacks of porphyria?
Hemein (IV injection) & glucose (needed for succynil coA)
How is porphyria photosensitivity managed?
B-carotene (anti oxidant) & phlebotomy (removing porphyrins)
What does MPS stand for?
Mononuclear Phagocyte system (macrophages of liver & spleen)
What is the biochemistry of kernicterus ?
Drugs displace bilirubin in liver releasing it into the CNS
At what level of blood bilirubin is it considered jaundice
2-3mg/dl
How many a-helices does a-globin have ?
7
How many a-helices does b-globin have ?
8
How many a-helices does myoglobin have ?
8
What is Le Chatalier principle?
When H+ decrease the sigmoidal curve is shifted to the left
What is bohr effect
Affinity of o2 decreasing with increased co2
What is the mirror effect of bohr in the lungs?
Haldane effect
How much higher is the affinity of Hb for CO than for O2?
220x
What is the main mode of transport for CO2
In plasma as HCO3- (80%)
What types of Hb does the yolk sac produce?
Gower & Portland
Which chromosome is the gene for a-globin on?
16
Which chromosome is the gene for b-globin on?
11
Position of amino acid affected in sickle cell anemia?
6th
How does hydroxyurea help with sickle cell anemia?
It increase transcription of HbF
What does HbC look like under microscope?
Target cells
What is the name of the enzyme that corrects oxidation of ferrous in hemoglobin?
NADH-Cyt b5 reductase
What diseases cause chocolate cyanosis in blood?
Methemoglobinemia
How does methemoglobinemia happen?
Resistance to ferric reducing enzyme NADH-Cyt b5 reductase
How is methemoglobinemia treated?
Methylene blue or vitamin C
Why is sickle cell anemia considered extravascular?
Most hemolysis occurs in liver in spleen because of slow blood flow increasing sickling
Inheritance pattern of porphyrias?
Autosomal dominant
What enzyme deficiency causes conginetal erythropoietic porphyria ?
Uroporphyrinogen III synthase