MT (AAB) Hematology Q&A

What is hemoglobin composed of? - Answer- 4 heme, 4 iron, 4 globins What disorder does a defect in heme synthesis lead to? - Answer- porphyria What is the function of the enzyme methemoglobin-cytochrome C reductase in a red blood cell? - Answer- to keep iron in the ferrous state Which hemoglobin has a 200 times greater binding capacity for the hemoglobin molecule than oxygen? - Answer- carboxyhemoglobin What product is formed when ferrous iron of hemoglobin is oxidized to the ferric state? - Answer- methemoglobin Which hemoglobin derivative causes irreversible changes in teh red blood cells? - Answer- sulfhemoglobin Which of the following hemoglobins is NOT normally present in a normal adult - Answer- Hb-S Which embryonic hemoglobin is normally found in newborns - Answer- Hb-F What is the most abundant hemoglobin in a newborn? - Answer- Hb-F What is the molecular structure of hemoglobin S? - Answer- Valine replaces glutamic acid in the 6th position of the beta chain Which of the following hemoglobins is insoluble under lowered oxygen tensions? - Answer- Hb-S What laboratory test is used to confirm the specific diagnosis of sickle cell anemia - Answer- hemoglobin electrophoresis In the solubility test for hemoglobin S, what is the reagent responsible for the reduction of the hemoglobin molecule? - Answer- sodium dithionite In hemoglobin C, what replaces glutamic acid? - Answer- lysine Which RBC inclusion is characteristic of hemoglobin C disease? - Answer- rod-shaped crystals What is hemoglobin F composed o? - Answer- 2 alpha + 2 gamma chains Which hemoglo