Aerobic respiration provides the energy required by all living organisms to function normally, as muscle movement and certain cell reactions are reliant on energy the transport of oxygen to the cells of tissues and organs by blood vessels is vital for respiration to occur. Oxygen is carried in red blood cells by the pigment haemoglobin, a globular protein consisting of four polypeptide chains. Both of these components of blood are structured specifically to carry out their functions of oxygen transport, hence ensuring efficient respiration.
Erythrocytes, or red blood cells, possess a unique structure that enables them to play their role in oxygen transport. They are small, at 7ÃÂ¼m in diameter, compared to that of average animal cells (approximately 20ÃÂ¼m). This allows them to be transported via the thin-walled capillaries, which have very small lumen of less than 8ÃÂ¼m in diameter, carrying oxygen as close as possible to the respiring tissues.
Haemoglobin within the small red blood cell can exchange oxygen with the external environment quickly, as they are close to the plasma membrane; this again allows efficient diffusion of oxygen.
Red blood cells are described as biconcave discs, flat, with a dent in both sides. This shape defines the cell's large surface area to volume ratio, indicating that oxygen can be transferred quickly between the cell and its surroundings, as haemoglobin molecules are close to the cell plasma membrane.
Unlike general animal cells, erythrocytes lack nuclei, mitochondrion and endoplasmic reticulum, giving space more haemoglobin can be carried by the red blood cells with such a structure, hence increasing the number of oxygen molecules being transported. The structure of red blood cells maximizes the amount of oxygen carried in the blood and the rate at which they reach and diffuse into oxygen requiring cells.
Oxygen is combined with haemoglobin in red...