Myoglobin - High Yield Topic Series

Myoglobin is a protein found in muscle tissues that binds and stores oxygen. It consists of a single polypeptide chain, which means it has only one subunit. Each myoglobin molecule can bind to only one molecule of oxygen, hence the number of oxygen molecules carried by myoglobin is 1. Therefore, the correct answer is 1,1,1.

Myoglobin acts as an oxygen reservoir in muscle tissues. It stores oxygen molecules and releases them when needed during periods of low oxygen availability. This allows muscles to continue functioning properly even in oxygen-deprived conditions. Myoglobin has a higher affinity for oxygen than hemoglobin, making it a more efficient oxygen storage molecule. Its role as an oxygen reservoir helps to ensure an adequate oxygen supply to the muscles, especially during intense physical activity.

The explanation for the given correct answer is that cooperative binding refers to the phenomenon where the binding of one molecule of a ligand to a protein increases the affinity of the remaining binding sites for the same ligand. Hemoglobin exhibits cooperative binding, where the binding of oxygen to one subunit of the protein increases the affinity of the remaining subunits for oxygen. This allows hemoglobin to efficiently pick up oxygen in the lungs and release it in the tissues. On the other hand, myoglobin does not exhibit cooperative binding as it only has one subunit and does not undergo conformational changes upon oxygen binding.

The shape of the oxygen dissociation curve of myoglobin is hyperbola. This is because myoglobin has a high affinity for oxygen at low partial pressures, meaning it binds to oxygen strongly in environments with low oxygen levels. As the partial pressure of oxygen increases, myoglobin becomes saturated with oxygen and its binding capacity decreases. This results in a hyperbolic curve, where the rate of oxygen binding slows down as the oxygen concentration increases.