Question

The aggregation of Hb S occurs in the ___ state, thus the formation of aggregates is likely to occur at ___.

a) Oxygenated; high pH
b) Deoxygenated; low pH
c) Oxygenated; low pH
d) Deoxygenated; high pH

Answer 1

The aggregation of HbS happens in the deoxygenated state and is more likely to occur at a low pH, causing red blood cells to deform into a sickle shape and result in health complications.

Step-by-step explanation:

The aggregation of hemoglobin S (HbS) occurs in the deoxygenated state, thus the formation of aggregates is likely to occur at low pH. Under conditions where the pH is lowered, there is a decrease in the affinity of hemoglobin for oxygen, leading to the release of oxygen from the hemoglobin molecule. This deoxygenation of HbS facilitates the clumping of hemoglobin molecules, which can lead to the sickling of red blood cells characteristic of sickle-cell anemia. It is this deoxygenated state of HbS at a low pH that supports the aggregation process, forming long, rigid fibers that cause the red blood cells to adopt a sickle shape, impeding their passage through capillaries and leading to various health complications.