The lowering of pH near metabolizing tissues is known as the ___________ effect.

The suitable term that describes the lowering of pH near metabolizing tissues is indeed the Bohr effect. This physiological phenomenon refers to the process whereby increased carbon dioxide levels (produced during metabolism) lead to a decrease in pH in the surrounding tissues. As the pH level drops, the affinity of hemoglobin for oxygen decreases, facilitating the release of oxygen where it is most needed—such as in actively metabolizing tissues.

This effect is critical in promoting efficient oxygen delivery throughout the body. In tissues that are actively consuming oxygen and producing carbon dioxide, the resulting increase in carbon dioxide (and consequently a decrease in pH) enhances oxygen unloading from hemoglobin. Thus, the Bohr effect is essentially a mechanism that ensures that areas of high metabolic activity receive adequate oxygen supply.

The other terms listed do not convey this specific physiological relationship: the Michaelis effect pertains to enzyme kinetics and substrate affinity, the Hill effect relates to the binding of oxygen to hemoglobin under various conditions, and Locke is not associated with any recognized biochemistry concept related to oxygen transport or pH changes in tissues.