Final answer:
The binding of oxygen to myoglobin gives a hyperbolic shaped curve, while hemoglobin's oxygen-binding curve is sigmoidal due to its cooperative binding behavior. Therefore, correct option is c.
Step-by-step explanation:
A plot of the binding of oxygen to myoglobin as a function of pO2 gives a hyperbolic shape; a similar plot for hemoglobin gives a sigmoidal shape. This difference is due to the binding properties and cooperative behavior of the proteins.
Myoglobin's oxygen-binding curve is a simple equilibrium between deoxy- and oxymyoglobin and is mathematically described as hyperbolic, suggesting that myoglobin has a high affinity for oxygen across a range of oxygen pressures. Hemoglobin, however, exhibits a more complex behavior known as cooperativity.
This means that the binding of each subsequent oxygen molecule to hemoglobin affects the affinity of the remaining sites available for oxygen, resulting in a sigmoidal, or S-shaped, curve on the graph.
The initial binding of oxygen results in a low affinity, which increases as more oxygen molecules bind until it reaches a point where the hemoglobin is nearly saturated, and then the affinity decreases for the final binding sites.