Why do you turn a C-terminal aminoacid's carboxyl group into an ester before reducing it to an alcohol? Why not just use LiAlH4 and do it in one step? This is to determine the C-terminal aminoacid in a peptide

Esters are both inorganic and organic acids ... Regarding the second question, it is believed that it is carried out in this way in order to recognize the C-terminal amino acid in a peptide within a protein

Explanation:

The explanation of this question is according to what was interpreted in the question, since it is considered that it is poorly written ...

What happens in this chemical reaction is that it first becomes an ester (organic or inorganic acid) so that it is later recognized in the complex peptide structure.

Answer: To determine the C-terminal amino acid in a peptide

Explanation: To determine C-terminal residue, either of chemical reagent or the enzyme is used carboxypeptidase. The chemical reagent hydrazine forms aminoacyl hydrazides with every residue except the C terminus The C terminus is identified by chromatographic procedures.

Carboxypeptidase is an exopeptidase that specifically hydrolyzes the C-terminal peptide bond and releases the C-terminal amino acid. There two problems associated with its use: the continuous action of the enzyme and the substrate specificity of the enzyme. This continuous action may yield the second, third, and additional residues from some chains even before the terminal residues on every chain are quantitatively released. Therefore making it difficult to determine which residue is the C terminus.