Question

Explain why different blood types would either be accepted or rejected by a recipient.

Relate the structure and function of hemoglobin in its role of respiratory gas distribution.

Explain the developmental processes that lead red blood cell formation.

Answer 1

1.

Blood types are decided on basis of presence or absence of presence or absence of antigens on the surface of RBC. Blood of recipient is clumbed if different blood type containing different antigen on RBC surface is transfused. RBC of only donor is affacted as antibodies in donor blood get diluted in recipient blood.

2.

Heamoglobin is a heterotetramer of two alpha and two beta chains. Alpha chain is 141 and and beta chain is 146 aa residue long and each chain is associated with a prosthetic group as heme. Heme contain Fe as central metal atom and associated with co- ordinate bond at proximal histidine and binds with oxygen at distal histidine by hydrogen bonding. Binding of Oxygen is co-operative and beta chain binds with different modulator and also with CO₂ and causes the exchange of gases according to their partial pressure differences.

3.

The process leading to formation of RBC is called erythropoiesis and takes place in bone marrow. Hematopoietic stem cell - a multipotent stem cell is developed into myeloid erthroid cell which us unipotent. A hormone is released by kidney by the cells of peritubular Capillaries called erythropoietin which is necessary for the production of RBC and released when their is lower level of oxygen in blood. Erythropoiesis binds on the surface of myeloid erythroid cells and causes synthesis of anti-apoptotic proteins and formation pf RBC. In early stages RBCs are nucleated but later on become enucleated to become fully functional.