Final answer:
Myoglobin and hemoglobin are both proteins involved in oxygen transport. Myoglobin has a higher ratio of nonpolar to polar amino acids, while hemoglobin has a more polar amino acid composition. This difference in composition reflects their specific functions in oxygen binding and release.
Step-by-step explanation:
Hemoglobin and myoglobin are both proteins involved in oxygen transport. Myoglobin is a single subunit protein, while hemoglobin consists of four subunits. Due to the difference in their structures, we would expect a molecule of myoglobin to have a greater ratio of nonpolar to polar amino acids compared to a subunit of hemoglobin.
Myoglobin is found in muscle cells and has a higher affinity for oxygen, as it needs to hold onto oxygen in low-oxygen environments. Therefore, myoglobin has a higher proportion of nonpolar amino acids that help it bind to the oxygen molecule more tightly.
Hemoglobin, on the other hand, needs to be able to release oxygen in tissues where oxygen concentration is low. It has a more polar amino acid composition, allowing it to exhibit cooperative binding, which means that as one subunit of hemoglobin binds to oxygen, the remaining subunits become more receptive to oxygen binding as well.