Please find attached.

amino acid and aldehyde reaction will give schiff base ( imine ) compounds , in this this reaction u need 1. solubility of reactants 2. temperature bellow 80oC 3. only 2 hours reaction do not increase reaction time.

Equimolar ratio of amine and aldehyde condensed to give imine and water. Sometimes formed imine is more sensitive to by product water so we have to use Dean stack apparatus to remove by product water to get imine. It's need morethan 100deg C temperature.

What is the effect of the Zwitterion here?

Do we need an acid or base like NaOH or HCl as catalyst?

You can use acetic acid as a catalyst

Ok, Thanks

Condensation process aldehyde with amino acids depending on 2-3 drops of glacial acetic acid give us imine group ( schiff base ) in ethanol as solvent .

Regards

https://chem.libretexts.org/Bookshelves/Organic_Chemistry/Book%3A_Basic_Principles_of_Organic_Chemistry_(Roberts_and_Caserio)/25%3A_Amino_Acids%2C_Peptides%2C_and_Proteins/25.05%3A_Reactions_of_Amino_Acids