The extracellular hemoglobin (HBL) from the blood sucking-leech, Marcrobdella de

Question

The extracellular hemoglobin (HBL) from the blood sucking-leech, Marcrobdella decora, has been characterized. HBL is an extremely large, 3600-kilodalton hemoglobin with many more subuntis than human hemoglobin. Oxygen dissociation curves are shown in the figure below for both the native (polymeric) leech hemoglobin (shown as HBL), and when subunits are dissociated and resembled as a tetramer (indicated by T), and also as a monomer (shown as M). Answer the questions below about the leech hemoglobin.

1. Which from of the leech hemoglobin has the highest oxygen binding affinity?

2. Which form of hemoglobin would have the greatest likelihood of offloading oxygen?

3. What is the P50 of leech hemoglobin (HBL)?

4. If the blood of the leech (HBL) and humans (HbA) co-mingle, in which directin would oxygen flow? A or B

A. From HbA to HBL

B. From HBL to HbA

Explanation / Answer

1.If the curve shifts towards left , the hemoglobin has higher affinity of oxygen. Similarly , shift toward the right means low affinity for oxygen .

We can see that , the curve for the monomer (M) is most towards the lef , which means it has highest affinity for oxygen.

2. The hemoglobin which has the lowest affinity for the oxygen , which means the curve on the right side will have low oxygen binding capacity, or high oxygen offloading capacity .

this means the HBL hemoglobin will have the most likelihood of offloading oxygen.

3.p50 is the value pO2 when the hemoglobin is 50% saturated with oxygen .

for HBL , we can see from the graph , it is 5 Torr.

4. As the HBL is more towards the right as compared to the hemoglobin , it willl easily give up on oxygen easily. so the flow from the HBL to HbA.

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.