The mutated form of hemoglobin (hemoglobin S, or HbS) in sickle-cell anemia results from the replacement of a glutamate residue by a valine at position 6 in the b chain of the protein. (Normal hemoglobin is designated HbA)Under conditions of low (O2), HbS aggregates and distorts the red blood cell into a sickle shape. Sickled red blood cells are relatively inflexible and may clog capillary beds, causing pain and tissue damage. The sickled red blood cells also have a shorter life span leading to anemia. a) Which of the following amino acids would you expect to produce a similar sickling effect if substituted for Val at position 6?1. arginine2. leucine3. lysine4. phenylalanine5. alanineb) Sickling occurs in deoxyhemoglobin S, but not in oxyhemoglobin S. Oxyhemoglobin has a small hydrophobic "pocket" in a B chain region located in the interior of the protein. In deoxyhemoglobin S, Val 6 interacts with this surface pocket leading to aggregation of HbS. Choose two amino acids that would be reasonable canidates for the pocket-Val 6 interaction.1. phenylalanine2. leucine3. serine4. arginine5. glutamatec) How does HbS aggregation occur in sickle-cell anemia? Place the steps in the correct order. Note that deoxyhemoglobin is in the T state; oxyhemaglobin is in the r state.