Intro to Amino Acids Practice Problems

Do the following α-amino acids have an aromatic ring, sulfur-containing group, hydroxyl group, or alkyl group side chain?

Are the following molecules α-amino acids? Why?

Why is the solubility of proteins in water lower at their isoelectronic points?

Which will increase the solubility of the zwitterion of lysine in water?

A person suffering from sickle-cell anemia may experience yellowing of the skin, swelling in the hands and feet, recurring pain, and eyesight problems. A series of blood tests and a test to identify hemoglobin types are done to diagnose whether the anemia is caused by sickle-cell anemia. Which lab test determines if a person has sickle-cell anemia, has the sickle-cell trait, or lacks the sickle-cell gene?

Is cysteine chiral? Justify your answer. If it is chiral, draw its structure and identify the chiral atom.

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.