• Textbooks have said for decades that haemoglobin is found in the red blood cells (RBCs), that it makes blood red, carries oxygen, and is essential for our survival.
• In a study published in Nature, scientists from China have reported that chondrocytes – cells that make cartilage, the connecting tissue between bones – also make haemoglobin and seem to depend on it for their survival.

ABOUT HEMOGLOBIN

• It is an iron-containing protein found in the red blood cells that carries oxygen from the lungs to the body’s tissues and returns carbon dioxide from the tissues back to the lungs.
• It is made up of four protein molecules (globulin chains) that are connected together.
• Haemoglobin forms an unstable reversible bond with oxygen.
  • In oxygenated state, it is called oxyhemoglobin (bright red) and in reduced state it is called deoxyhemoglobin (purple-blue).
• It is present in RBCs of vertebrates.
• All vertebrates except cold-water ice fish transport oxygen via haemoglobin.
• Haemoglobin develops in cells in bone marrow that become RBCs.
• Haemoglobin levels vary from person to person. Men usually have higher levels than women.
• A low haemoglobin level is referred to as anemia or low red blood count.
  • Reasons include- loss of blood, nutritional deficiency, bone marrow problems, suppression by red blood cell synthesis by chemotherapy drugs, kidney failure, and abnormal hemoglobin structure (sickle cell anemia or thalassemia).