Fundamentals of Biochemistry Third Edition Fundamentals of Biochemistry Third Edition Chapter 4 Amino Acids Chapter 4 Amino Acids Copyright © 2008 by John Wiley & Sons, Inc. Donald Voet Judith G. Voet Charlotte W. Pratt

Therefore, an alpha amino acid

Figure 4-2 amphoteric = acid and base functionality zwitterion = both positive and negative charges on ion

Table 4-1 part 1

Figure 4-4

Table 4-1 part 2

Table 4-1 part 3

Figure 4-5

Table 4-1 part 4

Figure 4-7

The formation of a peptide bond

The formation of a disulfide bond

Lettering the carbons on the side chains

The formation of a polypeptide Calculate this peptide’s isoelectric point (pI)

Figure 4-9 Determining the optical activity of a molecule “L” and “D” are not related to this

Enantiomers are stereoisomers related by a reflection Stereoisomers with more than one chiral center are diastereomers – consider isoleucine

Emil Fischer (1891)

All biologically used amino acids are in the L- configuration

The “other” stereoisomer convention

Many drugs are amino acid analogues

Non-standard, but biologically interesting, amino acids

Spontaneous cyclization of the three amino acids (out of 238) creates the fluorophore