(A Level) Amides, amino acids and peptides

Learning objectives

Describe the formation of amides from ammonia or primary amines with acyl chlorides, their hydrolysis by aqueous acid or alkali, and their reduction to amines with LiAlH₄

Explain, using delocalisation of the nitrogen lone pair into the C=O group, why amides are barely basic compared with amines

Explain how an amino acid exists as a zwitterion, how its charge changes in acidic and in alkaline solution, and what its isoelectric point means

Draw the dipeptides and tripeptides formed when amino acids join through peptide (amide) links, and identify the water lost at each link

Predict and explain how amino acids and dipeptides move in electrophoresis at a given pH, using their net charge and relative size