Question

Address the need to get oxygen to the muscles and get rid of Co2, as well as how the muscles cells get the energy needed to continue contracting.

Answer 1

Oxygen is carried in your blood stream by the red blood cells. Within the red blood cell there is a specialised protein molecule called Haemoglobin.

Red blood cells are specialised to carry oxygen through their lack of a nucleus giving them a biconcave shape and increasing their surface area. The red colour comes from the presence of iron in the haemoglobin molecules.

When the blood enters the lungs it is only ever one cell away from the air within the lungs. The constant flowing of the blood and the constant tidal flow of air in and out of the lungs ensures a concentration gradient is maintained at all times. This concentration gradient leads to carbon dioxide leaving the blood and oxygen entering it all by simple diffusion.

Blood is transported around the body by the pumping of the heart. The constant flow also helps to maintain a concentration gradient and encourages oxygen to disassociate from the oxyhaemoglobin complex within the red blood cells when the blood flows past areas of low oxygen concentration.

During times of high activity the muscles are respiring at an increased rate. This increase produces a corresponding increase in the amount of oxygen required and the amount of carbon dioxide produced. This is compensated for by an increased heart rate and the fact that oxygen will diffuse more rapidly in these situations.

As the blood flows past the muscles oxygen diffuses into the muscle tissue. If the oxygen is not immediately required it can be stored in myoglobin in the muscle tissue.

Respiration is the production of ATP from ADP or AMP (Adenosine tri, di and mono phosphate respectively) a high energy molecule that serves as a currency for energy in cells.Aerobic respiration requires oxygen and glucose and produces on average 30 molecules of ATP per molecule of glucose. Anaerobic respiration does not require oxygen but only produces 2 molecules of ATP per molecule of glucose; it also produces toxic lactic acid that needs to be metabolised in the presence of oxygen to avoid poisoning the body tissue.