What is the oxygen affinity of T-form hemoglobin?

T-form hemoglobin, or tense form hemoglobin, has a low affinity for oxygen. This is the form of hemoglobin that is predominant in the deoxygenated state. The T-form is stabilized by greater interactions between the beta chains of the hemoglobin molecule, leading to a more rigid structure that binds to oxygen less effectively.

When hemoglobin is in the T-state, it is more likely to release oxygen to the tissues, which is crucial for providing adequate oxygen delivery where it is needed most. This characteristic is essential for the physiological function of hemoglobin in transporting oxygen; as tissues consume oxygen, the lower affinity of T-form hemoglobin facilitates the release of oxygen.

In contrast, the R-form or relaxed form of hemoglobin has a high affinity for oxygen, allowing it to bind oxygen more effectively and transport it from the lungs to the tissues. Understanding the balance between these two forms is vital for appreciating how hemoglobin regulates oxygen delivery according to the varying needs of different tissues under different physiological conditions.