Complex sentence: In general, each residue would produce an observable peak in the spectra, with the exception of proline which lacks an amide proton, and normally the N-terminal residue (which has an NH 3 + group attached) is not readily observable.
Split into simpler sentences: In general, each residue would produce an observable peak in the spectra from, with the exception of proline which lacks an amide proton. Normally the N-terminal residue (which has an NH 3 + group attached) is not readily observable.