Which two muscle proteins are responsible for binding to oxygen and release it when oxygen levels are low?

Myoglobin and hemoglobin are indeed the two muscle proteins responsible for binding to oxygen and releasing it when oxygen levels drop.

Myoglobin, found within muscle tissues, serves as an oxygen reservoir, releasing its bound oxygen as muscle activity increases and oxygen demand rises. This is especially crucial during intense exercise when the muscles require additional oxygen to sustain their activity.

Hemoglobin, located in red blood cells, carries oxygen from the lungs to the tissues. It has a similar function to myoglobin but operates on a larger scale, transporting oxygen throughout the body. When blood oxygen levels drop, hemoglobin can release oxygen to the tissues, including exercising muscles.

Together, these proteins play a vital role in maintaining oxygen supply during physical activity, ensuring that muscles receive adequate oxygen to function effectively under varying physiological conditions. This relationship between oxygen binding and release is essential for metabolic processes and energy production during muscle contraction.