Gas Transport in Blood MCQs

Oxygen Carrying Capacity of Hemoglobin Each gram of hemoglobin transport 1.34 ml. of oxygen So, here in the question, its 14 x 1.34 =18 Reference: Ganong, 25th edition/page no.640

Myoglobin is the iron - containing pigment that stores oxygen mainly present in skeletal muscle Each molecule of myoglobin can bind with only one molecule of oxygen myoglobin binds with oxygen with increased affinity leading to loading of oxygen (left shift) Reference: Ganong, 25 th edition page no.641

DPG mutase enzyme is inhibited by acid leading to decrease in 2,3 DPG formation. This leads to left shift of OHDC and less oxygen delivery in tissue So, Acid Citrate Dextrose is not preferred in hypoxic patient. Reference: Ganong 25th edition page no.641

The decrease in O 2 affinity of hemoglobin when pH of blood falls (PCO 2 rises) is called the Bohr effect. This leads to release of oxygen at tissues Reference: Ganong, 25th edition page no.641

Chloride Shift Also called as Hamburger phenomenon The channel responsible for chloride shift is called as anion exchanger 1 (AE 1). It is also called as Band 3 protein present in RBC membrane HCO3 - leaves the RBCs in exchange for Cl - chloride shift) and is transported to the lungs in the plasma Cl -ion is an osmotically active particle that drags water along with it into the RBCs Since RBCs take up water, it increases in size. This is the reason why hematocrit of venous blood is normally 3% greater than that of arterial blood In lungs, chloride shift happen in opposite direction leading to shrinkage of RBC's Reference: Ganong 25th edition/page no.641

P50-is the partial pressure of oxygen at which hemoglobin saturation with oxygen is 50% The value of P50 is around 25-27 mm Hg Hemoglobin affinity for O2 is inversely related to the P 50 If the oxyhemoglobin dissociation curve is shifted to the right, the P 50 increases Decrease in pH (acidosis) causes right shift of ODC. So, the answer is pH Reference: Ganong, 25th edition page no.641

2,3-Bisphosphoglycerate(2,3-BPG) is found in large amounts in red cells. It is formed from 3-phosphoglyceraldehyde, which is a product of glycolysis via the Embden-Meyerhof pathway. It is a highly charged anion that binds to the β chains of deoxyhemoglobin leading to unloading of oxygen to tissues . One mole of deoxyhemoglobin(Taut form or T form of hemoglobin) binds 1 mol of 2,3-BPG. Other options: 2,3-BPG does not bind to alpha and gamma chains.

2,3-Bisphosphoglycerate(2,3-BPG) is found in large amounts in red cells. It is formed from 3-phosphoglyceraldehyde, which is a product of glycolysis via the Embden-Meyerh of pathway. It is a highly charged anion that binds to the β chains of deoxyhemoglobin leading to unloading of oxygen to tissues. One mole of deoxyhemoglobin(Taut form or T form of hemoglobin) binds 1 mol of 2,3-BPG. Other options: 2,3-BPG does not bind to alpha and gamma chains.