Does the affinity of myoglobin for oxygen change when
oxygen concentration changes?
Im not really sure how to answer this. I know that myoglobin has very strong affinity for oxygen so once myoglobin is in the presence of oxygen it will react right away until it is fully saturated but im sure if that would be dependent on O2 concentration
rom my understanding, these curves never truly obtain 100% saturation. Theoretically it can, but 100% saturation is never obtained. Hemoglobin is a protein and oxygen is it's substrate. A protein's affinity for its substrate never changes no matter how much of a substrate a protein is saturated with. There could be ten substrate molecules for one protein or ten protein molecules for one substrate. No matter the numbers of each, a protein's affinity for is substrate does not change.
thank you
Hemoglobin and myoglobin are both proteins and the statement applies to both.
The affinity of myoglobin for oxygen does indeed change with changes in oxygen concentration. Myoglobin is a protein found in muscle cells that is responsible for storing and transporting oxygen. It has a high affinity for oxygen, meaning it readily binds to oxygen molecules when they are available.
At low oxygen concentrations, myoglobin will quickly bind to any available oxygen molecules in its vicinity until it becomes fully saturated. As the concentration of oxygen increases, more oxygen molecules will be available for myoglobin to bind to, thereby increasing the saturation level.
However, it is important to note that myoglobin does not exhibit cooperative binding like hemoglobin, another oxygen-binding protein found in red blood cells. Cooperative binding means that hemoglobin's affinity for oxygen increases as each oxygen molecule binds to it. Myoglobin, on the other hand, does not exhibit this behavior. It has a single oxygen-binding site and does not undergo significant conformational changes upon binding oxygen.
In summary, the affinity of myoglobin for oxygen changes indirectly with changes in oxygen concentration. As the oxygen concentration increases, myoglobin will bind more oxygen molecules until it becomes fully saturated. Conversely, at lower oxygen concentrations, myoglobin releases oxygen molecules more readily.