Can I build a peptide by typing amino acid strings together?
In some versions of ChemDraw, yes. Open the text tool. Type H, then type the three letter abbreviation for the amino acid as defined in the List of Nicknames (ChemDraw File menu), then end the sequence with OH i.e. HGluGlyOH Now click on the lasso tool which will highlight the entire text box. Finally, choose the Expand Label command in the Structure menu to view the structure. Please note that your version of ChemDraw may not have the Expand Label command. This feature is only available in certain versions of ChemDraw. Also note that some versions of ChemDraw can define new Nicknames. See your ChemDraw manual for more details about the Expand Label command and defining Nicknames.