BIOCHEM MIDTERM CRAM (TOPIC 3) Amino Acids

Gebneric Amino Acid at pH 7

relation between pKa and pH, and the pH of the functional groups

if pH<pKa, the group holds onto its hydrogen

if pH>pKa then group loses its hydrogen

COOH group pKa is 2

NH3 group pKa is 9.5

Amino Acid Side Chains Group A

Alanine

Valine

Leucine

Isoleucine

Phenylalanine

Tryptophan

Methionine

Proline

Amino Acid Side Chains (Group B)

Glycine

Serine

Threonine

Tyrosine

Which R groups have ionizable functional groups?

 Neutral, Polar: Tyr, Cys, His

 Charged, Polar: Asp, Glu, Lys, Arg

Cysteine

Cystine

Asparagine

Glutamine

Histidine

Hystidine as an Acid and Base

Amino Acid Side Chains (Group C)

Aspartate

Glutamate

Lysine

Arginine

Polar and non-polar side chains in protein structures