Erythrocyte Biochemistry Flashcards
Which of the following subunits make up fetal hemoglobin?
A. alpha2-beta2
B. alpha2-gamma2
C. gamma2-beta2
D. alpha2-alpha2
alpha2-gamma2
Which of the following correctly describes the conformation change of Hb upon O2 binfing to the heme iron?
A. Hb decreases affinity for O2
B. The proximal histidine and distal histidine both pull down the globin chain
C. The distal histidine helps stabilze the O2
D. The proximal histidine moves up and and releases its interaction with the globin chain
The distal histidine helps stabilze the O2
Which of the following correctly describes the effect of pH on O2 binding affinity of Hb?
A. Hb increases affinity for O2
B. Left Shift seen on O2 dissociation curve
C. Hb decreases affinity for O2
D. None of the above
Hb decreases affinity for O2
This is also seen in: increase 2,3-BPG, exercise or sickle cell anemia
Why does HbF binds O2 better than HbA?
HbF does not bind 2,3-BPG well
A third of our iron is stored in what 3 locations of our body?
Liver
Spleen
Bone Marrow
Which of the following is able to bind Ferric Iron (Fe3)?
A. Hepcidin
B. Ferroportin
C. Feroxidase
D. Ferritin
Ferritin
______ exports ferrous iron (Fe2) out of the cells and requires _________ to function. The exporting protein however is destroyed/regulated by ________
Ferroportin exports ferrous iron (Fe2) out of the cells and requires Hephaestin to function. The exporting protein however is destroyed/regulated by Hepcidin
Which of the following is correct about the transport of iron in the blood?
A. Transferrin binds and transports Fe2
B. Transferrin binds and transports Ferrous
C. Hepcidin binds and transports ferric
D. Transferrin binds and transports Fe3
Transferrin binds and transports Fe3
Which of the following is responsible for oxidizing animal product derived Ferrous to Ferric to be stored in Ferritin?
A. DMT-1 (Divalent Transporter)
B. Feroxidase/Cerruloplasmin
C. Feric Reductase
D. Duodenal Cytochrome-like B protein
E. C and D
F. A and B
Ferroxidase aka Cerruloplasmin
Which of the following is responsible for reducing Ferric to Ferrous in the presence of Vitamin C?
A. DMT-1 (Divalent Transporter)
B. Feroxidase/Cerruloplasmin
C. Feric Reductase
D. Duodenal Cytochrome-like B protein
E. C and D
F. A and B
C and D
Ferric Reductase
Duodenal Cytochrome-like B protein (dcytb)
Which of the following correctly expresses how transferrin is removed?
A. Combustion via an oxidation reaction
B. REceptor mediated endocytosis and internalized via COP2 coated puts into endosomes
C. TfR enodocytoses transferrin into clathrin coated pits
D. None of the above
TfR enodocytoses transferrin into clathrin coated pits
Which of the following regulates the expression of Hepcidin in the liver?
A. Human Homeostatic Iron Regulator Protein that is initiated irrespective of iron levels
B. HFE that is responsive to iron levels
C. Presence of Hemosiderin
D. None of the above
HFE that is responsive to iron levels
When iron levels are low which of the following is most likely to be occuring?
A. Hepcidin expression: decreases, Ferroportin: increases, Iron Absorption: increases
B. Hepcidin expression: increases , Ferroportin: decreases , Iron Absorption: decreases
C. Hepcidin expression: decreases , Ferroportin: increases , Iron Absorption: decreases
D. Hepcidin expression: decreases , Ferroportin: decreases , Iron Absorption: decreases
A. Hepcidin expression: decreases, Ferroportin: increases, Iron Absorption: increases
Which of the following is the correct clinical presentation of Hereditary Hemochromatosis?
A. IRon absorption decreases in heart, liver, and pancreas begin to fail
B. Iron absorption increases and accumulates in the bone marrow, heart, and spleen
C. Iron absorption increases and accumulates in the heart, liver, and pancreas
D. None of the above
Iron absorption increases and accumulates in the heart, liver, and pancreas
NOTE: HH is iron overload
RBC production is dependent on what two substances, who’s absence would lead to Megaloblastic anemia?
Folate (folic acid)
B12 (cobalamin)