Question

XXXXXX A scientist discovered a smal group of very sickly Zebra that struggle with their ability to breathe, hence it is difficult for them to tolerate long amount of strenuous running, like the other Zebra can in their community. All of these sickly Zebraxxare related and from one family. This scientist took this family of Zebra to a famous animal rescue habitat. Their blood samples were taken and sent to your lab for analysis.  

There is a severe defect in the Hemoglobin of these Zebra and excess, unused and unbound Fe (iron) in their blood. What specific part of the hemoglobin molecule do you predict is the source of the problem and why?  Why is this specific portion of Hemoglobin being defective affect the capacity of these Zebra to properly bind/move Oxygen? (50 words max)

Is the mutated hemoglobin of these Zebra still cooperative and why/why not? (30 words max)

ANSWER:  

You study the pathway that makes hemoglobin and find out that the Zebra do not have a mutated pathway at all. The problem is that they do have very little amounts of two critical molecules to make the large molecule in Part A.   You remember that when you took Chem 153A, your guest lecturer on Monday of Week 10 talked about this exact topic. What two molecules are not present in high enough quantities to make the molecule in Part A? What is one way you can easily fix this problem for the Zebra? (50 words max)

If you provide the fix from Part E, do you expect these Zebra to make a full recovery and produce normal Hemoglobin? Why or why not? (40 words max)

Answer 1

Hemoglobin molecule has two parts. Heme and globin. Heme portion is made of iron porphyrin ring. There are 4 pyrrole molecules forming the porphyrin ring , at the center of which is present Iron. In this molecule, there is defective iron porphyrin ring present. Iron binds to O2 to form oxyhemoglobin. Because of the defective iron porphyrin ring, O2 is not able to bind to hemoglobin molecule and there is also unbound Iron present in the blood.

Mutated hemoglobin can't bind to O2. Because Iron is important in binding to O2. If the mutated hemoglobin is not able to bind to Fe, then the hemoglobin O2 carrying capacity will also decrease. But there is some dissolved O2 carried in the plasma to supply O2 to all parts of the body.

Hemoglobin formation needs proteins, vitamins and Iron. Vitamins such as Folic acid, B12 are important in hemoglobin synthesis. Body uses folate to form heme molecule of hemoglobin. Vitamin B12 is also important in formation of hemoglobin and maturation of RBCs.

By taking these vitamins hemoglobin can be sufficiently formed and the Zebras can lead a normal life. They can normally run as they will have sufficient amount of hemoglobin in their blood.