
Which will increase the solubility of the zwitterion of lysine in water?
Which of the following amino acids has two chiral centers? Identify the two chiral centers using an asterisk (*).

Isoleucine is an amino acid that has two chiral centers. Provide the structure of L-isoleucine and indicate each chiral carbon. Identify the carbon atom that causes the D and L configuration.
Provide the structure of methionine and indicate the chiral carbon, if any, using arrows.
Which of the following proteins have their functions correctly matched?
i. Gluten: storage protein
ii. Keratin: biological catalyst
iii. Immunoglobulin: defense proteins
iv. Pepsin: structural protein
The zwitterion structure of leucine (pI = 6.0) is shown below. Draw the predominant structure of leucine at pH 2.0 and determine its net charge.