1. Carbon dioxide in the blood at normal levels is in equilibrium. This is meant to act as a buffer to
keep blood’s pH at optimal levels (7.4). When the levels of CO2 increase, it will also increase the
amount of carbonic acid, bicarbonate, and protons. As the amount of protons increases, the pH
decreases, and vice versa. If the pH is too high or too low it can alter enzyme structure impairing
2. When CO2 increases in the blood, it reacts with water to produce carbonic acid. Lactic acid also
decreases pH stimulating chemoreceptors to send nerve impulses to the respiration center in
the medulla oblongata which controls the diaphragm and abdominal muscles.
3. The difference between total lung capacity and vital capacity is that vital capacity is the
maximum amount of air that can be voluntarily moved into or out of the lungs. Total lung
capacity includes residual volume which is the air left in the lungs after maximal expiration.