State the order of basicity for ethanamide, diethylamine and ethylamine in aqueous solution. Give a reason for your answer. (most basic $>$ $>$ least basic)
The amino acid alanine, $\text{H}_2\text{NCH(CH}_3)\text{COOH}$, can function as a buffer.
Define a buffer solution clearly.
Write two equations to show how an aqueous solution of alanine can behave as a buffer solution.
Glutamic acid is another amino acid that can act as a buffer.
Draw the skeletal formula of glutamic acid.
Draw the structure for the dipeptide, ala-glu, formed from one molecule of alanine and one molecule of glutamic acid. The peptide bond that forms should be shown.
The isoelectric point of alanine is $6.0$ and of glutamic acid is $3.2$. A mixture containing the dipeptide, ala-glu, together with its two constituent amino acids, alanine and glutamic acid, is analysed by electrophoresis using a buffer at $\text{pH} = 6.0$. Draw and label three spots on Fig. 7.2 to show the expected position of each of these three species after electrophoresis. Explain your answer.
Alanine, $\text{H}_2\text{NCH(CH}_3)\text{COOH}$, reacts with methanol to produce the ester G under certain conditions. The proton ($^1\text{H}$) NMR spectrum of G dissolved in $\text{D}_2\text{O}$ is shown in Fig. 7.3.
Complete Table 7.2 for the proton ($^1\text{H}$) NMR spectrum of $G$.
The proton ($^1\text{H}$) NMR spectrum of $G$ dissolved in $\text{CDCl}_3$ is recorded. Describe how this spectrum differs from the proton NMR spectrum in $\text{D}_2\text{O}$ shown in Fig. 7.3. Explain your answer.