Sickle-cell anemia is a striking example of the drastic effect a single amino ac

Question

Sickle-cell anemia is a striking example of the drastic effect a single amino acid substitution can have on the structure and function of a protein. Part A Given the chemical nature of glutamate and valine. can you suggest why substitution of valine for glutamate at position 6 of the fi chain would be especially deleterious? The amino acid glutamate is hydrophobic and ionizes at cellular pH. whereas valine is hydrophilic and nonionic. The amino acid glutamate is hydrophilic and ionizes at cellular pH, whereas valine is hydrophobic and nonionic. The amino acid glutamate is hydrophilic and nonionic. whereas valine is hydrophobic and ionizes at cellular pH. The amino acid glutamate is hydrophobic and nonionic. whereas valine is hydrophilic and ionizes at cellular pH. Part B Choose amino acids that would be much less likely than valine to cause impairment of hemoglobin function if substituted for the glutamate at position 6 of the fi chain. serine. threonine. tyrosine. cysteine. aspartate threonine. tyrosine. cysteine. isoleucine tyrosine cysteine. aspartate isoleucine serine, threonine, tyrosine, isoleucine Part C Is it possible that two proteins could differ at several points in their amino acid sequence and still be very similar in structure and function? No, the substitutions always essentialy change elemental composition of proteins. Yes, if the substitutions are always of like-for-like amino acids in terms of chemical properties. Yes, if the substitutions are always of like-for-like amino acids in terms of elemental composition. No, the substitutions always essentialy change chemical properties of proteins.

Explanation / Answer

Part A: Amino acid glutamate is hydrophilic and ionizes at cellular pH, whwresa valine is hydrophobic and non ionic

Part B: serine, threonine, tyrosine, cysteine, aspartate

Part C: yes, if the substitutions are always of like for like amino acids in terms of elemental composition

Related Questions

Navigate

• Browse (All)
• Browse S
• Subjects

---

---

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