Tag: basics of blood and heart

Hemoglobin (Hb or Hgb ) is an iron-containing protein present in erythrocytes or Red blood cells(RBC) of almost all vertebrates. Each hemoglobin is made up of 4 subunits, 2 alpha subunits and 2 beta subunits. Each subunit surrounds the central heme group that contains iron and binds to one oxygen molecule. Hence each hemoglobin molecule can bind to four oxygen molecules. It carries oxygen from lungs to tissues. It also helps in the transportation of carbon dioxide, hydrogen ions back to the lungs from the tissues. Hence haemoglobin in the RBCs helps in the transport of oxygen and carbon dioxide.

A single haemoglobin molecule contains four haem groups, each capable of binding one molecule of oxygen, allowing a total of four oxygen molecules to be carried per haemoglobin molecule.

Carbon monoxide binds to haemoglobin with much higher affinity than oxygen, forming carboxyhaemoglobin. This effectively reduces the amount of free haemoglobin available to transport oxygen.

It is a standard physiological constant that 1 gram of pure haemoglobin can bind approximately 1.34 mL of oxygen when fully saturated.

(b) To maintain electrostatic neutrality of plasma, many chloride ions diffuse from plasma into RBCs and bicarbonate ions pass out. The chloride content of RBCs increase when oxygenated blood become deoxygenated. This is termed as chloride shift or Hamburger phenomenon.

While plasma carries some dissolved oxygen, the vast majority of oxygen transport in the body is carried by the blood, specifically within the red blood cells via haemoglobin.

Anaemia is defined as a condition marked by a deficiency of red blood cells or of haemoglobin in the blood, resulting in reduced oxygen transport capacity.

Haemoglobin synthesis begins during the early stages of erythropoiesis. It is first detectable in the intermediate normoblast stage.

Nerve impulses, heart pacemakers, and muscular movement via ATP are correct associations. Monocytes are white blood cells involved in phagocytosis and do not contain haemoglobin.