In fact, cysteines are the only amino acids capable of forming covalent bonds, which they do with their particular side chains. Because of side chain interactions, the sequence and location of amino acids in a particular protein guides where the bends and folds occur in that protein (Figure 1).
gas exchange between the pulmonary blood and lungs where oxygen from fresh air in lungs moves into the blood and excess CO2 from the blood moves into the lungs.xygen and carbon dioxide that are transported to and from the lungs and tissue cells where oxygen is pumped throughout the body is CO2 is pumped back into the lungs.
Gas exchange is a biological process through which different gases are transferred in opposite directions across a specialized respiratory surface. Gases are constantly required by, and produced as a by-product of, cellular and metabolic reactions, so an efficient system for their exchange is extremely important.uring physical exercise, excess carbon dioxide is produced as a result of increased respiration, and muscles and cells require increased oxygen. The body responds to this change by increasing the breathing rate, maximizing the rate of possible gas exchange.