Final answer:
The incorrect statement about hemoglobin's oxygen binding is that its affinity for oxygen increases in acidic conditions; in fact, it decreases, causing hemoglobin to release oxygen more easily in tissues (Bohr effect).
Step-by-step explanation:
The statement about hemoglobin's oxygen binding that is incorrect is C) Hemoglobin affinity for oxygen increases in acidic conditions. Actually, the affinity of hemoglobin for oxygen decreases in acidic conditions, which is a phenomenon referred to as the Bohr effect. When the level of carbon dioxide in the blood increases, it reacts with water to form bicarbonate and hydrogen ions, leading to a decrease in pH. This reduction in pH causes hemoglobin to release oxygen, corresponding to a right shift in the oxygen dissociation curve.
Hemoglobin binds oxygen cooperatively, meaning as one molecule of oxygen binds, the affinity for the next oxygen molecule increases until the hemoglobin is saturated. As the percent saturation of hemoglobin increases, it becomes more difficult for additional oxygen molecules to bind, reflecting the sigmoidal, or S-shaped, oxygen dissociation curve.