Biochemistry Question of the Day

Hemoglobin is an important component of red blood cells that allows for efficient delivery of oxygen from the lungs to tissues throughout the body. Without hemoglobin, oxygen would not be able to dissolve in the blood well enough to meet the metabolic needs of tissues. Hemoglobin is well-suited to this function because its affinity for oxygen varies depending on its chemical environment. Which of the following situations would cause a rightward shift on the oxygen dissociation curve for hemoglobin?