Question

Name the component of blood which transports oxygen.

Answer 1

The blood component that transports oxygen lacks a nucleus and has a lifespan of around 120 days. Sometimes, due to genetic variation it changes its shape and looks like a sickle, a disease known as Sickle Cell Anaemia.

Complete answer:
Red Blood Cells or erythrocytes help in the transportation of oxygen in blood. In the blood, hemoglobin is present which binds with oxygen and transport it to the cells.
-An unstable reversible bond with oxygen is created by hemoglobin. It is called oxyhemoglobin in the oxygenated state and is bright red; it is purplish blue in the reduced state.
-In cells in the bone marrow, which become red blood cells, hemoglobin is produced.
-Hemoglobin is broken down when red cells die: iron is rescued, proteins called transferrins are transferred to the bone marrow and used again in the development of fresh red blood cells; the remainder of the hemoglobin forms the basis of bilirubin, a chemical that is excreted into the bile and gives its distinctive yellow-brown color to the feces. ⠀
-Hemoglobin is a protein that is made up of four chains of polypeptides -alpha1, alpha2, β1, and β2. Each chain is attached to a group of hemes made up of porphyrin (a ring-like organic compound) attached to an iron atom.
-These iron-porphyrin complexes reversibly coordinate oxygen molecules, an ability directly related to hemoglobin’s role in the transport of oxygen in the blood.
-Each hemoglobin molecule, forming a tetrahedral structure, is made up of four heme groups surrounding a globin group.

Note:
-Heme, which accounts for just $4\%$ of the molecule's weight, is composed of a porphyrin-like organic compound to which an iron atom is attached.
-As the blood flows between the lungs and the tissues, it is the iron atom that connects oxygen.
-In each molecule of hemoglobin, there are four iron atoms, which can therefore bind four oxygen atoms.