A typical amino acid with one amino group and one carboxylic acid group, such as serine, can exist in water in several ionic forms. Suggest the forms of the amino acid at low pH and at high pH.

During the hydrolysis of proteins, some amino acids, such as tryptophan, do not survive the reaction conditions. Other amino acids, such as asparagine and glutamine, are modified. Referring to Table 1-7 (p. 39), which shows the structures of the 20 common amino acids, write the structures of the two amino acids that are formed when asparagine and glutamine decompose in hot, concentrated HCl.

Pick the FALSE statement: Since amino acids have functional groups that are strong acids, their structures depend on the pH of their environment. Cys has a sulfhydryl that can stabilize protein shape by forming noncovalent bonds. The R group in Ala is a methyl group. Aspartic acid and glutamic acid do not have amide groups. more than 1 of the above is false

Peptides Proteins Amino Acids How do amino acids exist in solution? What is the solubility in organic solvents, aqueous acids, aqueous bases?

Amino acids containing a nonpolar "R" group, such as an alkyl or aromatic, are in nature. acidic O hydrophobic O hydrophilic O basic

As we’ve discussed, a peptide bond is made when amino group of one amino acid combines with the carboxylic acid group of another amino acid (releasing a water molecule in the process). The C-N bond formed in this process is called a peptide bond. Peptide bonds have a few properties that might be unexpected. a) One property is that the molecular geometries around the C and N atom in the peptide bond are generally planar with bond angles of approximately 120 degrees. Provide an explanation for why the peptide bond would have this property, using Lewis structures, VSEPR theory and/or valence bond theory as appropriate.

Refer to the structure of procaine in the table in the essay “Local Anesthetics.” Using p-aminobenzoic acid, give equations showing how procaine and procaine monohydrochloride could be prepared. Which of the two possible amino functional groups in procaine will be protonated first? Defend your choice. (Hint: Consider resonance.)

All amino acids share a common structure, a central (alpha) carbon with four groups attached. Which of these is NOT one of the four groups attached to the alpha- carbon? O an R group an ammonium group (-NH3+) O a carboxylate group (-COO) a hydronium group

Proteins are formed when the group of one amino acid forms a peptide bond with the group of a second amino acid. OR group; H-bond + O NH3*, R group + O -COO, NH3 -COO, R group

Write a net ionic equation to show that piperidine, C5H11N, behaves as a Bronsted-Lowry base in water.