Haemoglobin is the red protein in blood cells and which carries oxygen and other gases to different parts of the body.
(a) arries life-sustaining oxygen from the lungs via blood cells to other cells throughout the body.
(b) carries away waste carbon dioxide from the cells to the lungs where it is exhaled.
(c) carries nitric oxide to and from body tissues, thus regulating the body's balance of this chemical, which is vital to various body functions including learning, memory and blood pressure.