How is Co2 removed from muscle fibre?

CO2 is removed from muscle fibres through several processes:

1. Diffusion: CO2 produced in muscle cells during metabolism can diffuse out of the cells and into the bloodstream due to the concentration gradient between the cells and the blood.

2. Myoglobin: Myoglobin is a protein found in muscle cells that binds to oxygen. When oxygen levels are high, myoglobin binds to oxygen, but when oxygen levels are low, myoglobin releases oxygen. This allows muscle cells to store oxygen and use it when needed, such as during periods of intense exercise. When myoglobin releases oxygen, it can also bind to CO2, allowing CO2 to be removed from the cells.

3. Carbonic anhydrase: Carbonic anhydrase is an enzyme found in muscle cells that catalyzes the reaction between carbon dioxide and water to form carbonic acid (H2CO3). Carbonic acid then dissociates into hydrogen ions (H+) and bicarbonate ions (HCO3-). The hydrogen ions are buffered by muscle proteins, while the bicarbonate ions are transported out of the cells into the bloodstream.

4. Transport by hemoglobin: Hemoglobin is a protein found in red blood cells that transports oxygen and carbon dioxide throughout the body. When hemoglobin binds to oxygen in the lungs, it also binds to a small amount of CO2, which is transported to the tissues. In the tissues, hemoglobin releases the oxygen, and the CO2 diffuses out of the blood and into the cells.

Once CO2 is removed from the muscle fibres, it is transported by the bloodstream to the lungs, where it is exhaled.