Gas exchange is the delivery of oxygen from the lungs to the bloodstream, and the elimination of carbon dioxide from the bloodstream to the lungs. It occurs in the lungs between the alveoli and a network of tiny blood vessels called capillaries, which are located in the walls of the alveoli.
They bind to an allosteric site which induces a conformational change that increases the affinity of the enzyme's active site for its substrate. This increases the reaction rate.