20. Aspartic acid has pKa values of 2.1, 3.9, and 9.8. Calculate the isoelectric point (pI) of aspartic acid. (A) 3.0 (B) 3.9 (C) 5.0 (D) 8.9

1. Which of the following is NOT a distinctive property of living systems? (A) Living organisms exhibit a high level of organization. (B) Biological structures are related to specific functions. (C) Living systems have the capacity for reproduction. (D) Living systems do not carry out energy transformation.