swer the following eight questions (a through h) based upon a tripeptide sequenc

Question

swer the following eight questions (a through h) based upon a tripeptide sequence of the following amino acids (one-letter codes are given): Q V K a) What is the full name of each of the three amino acids? Spelling counts, but capitalization does not. If one of the answers is an acidic amino acid, use the-ate ending instead of the -ic acid ending. Q: V: K: b) What is the three-letter code for each of the amino acids? Q: V: K: c) What is the overall charge on the tripeptide at physiological pH (pH 7 4)? umbee.an physiological p (pH 74)? Enter youranswer as a Enter your answer as a number, e.g., -1, 0, or 1 , ot 1 Number d) For each of the amino acids, is the side chain (R group) hydrophobic, polar but uncharged, positively (+)charged, or negatively() charged at physiological pH? Q: Select answer V: Select answer K: Select answer

Explanation / Answer

a) Q - Glutamine, V - Valine and K - Lysine.

b) Q - Glutamine : GAA or GAG; V Valine: GUU or GUC or GUA or GUG; K - Lysine: AAA or AAG

c) Since glutamine bears a negative charge on the side as well as the valine (-2). Lysine is basic amino acid that bears a net positive charge (+1) hence, overall charge of tripeptide is -2+1 = -1.

d) Q - glutamine bears negative charge, V - valine bears a negative charge and K - Lysine bears a positive charge.

e) The overall charge below pH 1 : no protonation observed at pH 1 for glutamine and valine but lysine loses the proton and hence, overall charge will be -2-1 = -3.

f) Over all charge at pH 12 would be same as at physiological pH -1.

g) At physiological pH of 7.4 hydrophobic interactions are observed between amino acids in the tripeptide. Option 3 is correct.

h) If the tripeptide was dissolved in a buffer at pH 8.5, the net charge does not change and would be +1 for lysine (most abundant chemical species).

Related Questions

Navigate

• Browse (All)
• Browse S
• Subjects

---

---

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