Multiple Choice
Lysine contains two amine groups (pKa values of 9.0 and 10.0) and a carboxylic acid group (pKa 2.2) . In a solution of pH 9.5, which of the following would best describe the protonation and charge state of lysine?
A) carboxylic acid: deprotonated and neutral; both amines: protonated and positive
B) carboxylic acid: deprotonated and negative; both amines: deprotonated and neutral
C) carboxylic acid: deprotonated and negative; amine (pKa 9.0) : deprotonated and neutral; amine (pKa 10.0) : protonated and positive
D) carboxylic acid: deprotonated and negative; amine (pKa 9.0) : protonated and positive; amine (pKa 10.0) : deprotonated and neutral
E) carboxylic acid: deprotonated and neutral; amine (pKa 9.0) : deprotonated and neutral; amine (pKa 10.0) : protonated and positive
Correct Answer:
Verified
Correct Answer:
Verified
Q7: Given the structure of a glucose molecule,
Q8: Which of the following acids or bases
Q9: If a buffer is made with the
Q10: Which of the following atoms could interact
Q11: If gastric juice has a pH of
Q13: Lactic acid is a common product of
Q14: Citric acid is a triprotic acid with
Q15: Since pK<sub>a</sub> = -log K<sub>a</sub>, which of
Q16: Which of the following best explains the
Q17: Imidazole is a commonly used buffer in