# Building a peptide from a given sequence

Welcome to the BALLView tutorial. It will show you some of BALLView's main features. The tutorial takes approximately 15 minutes and is divided in several steps, which have to be finished one by one. The button "Next" will be enabled after finishing each individual step.

We start by building a polypeptide from an aminoacid sequence. To do so, open the PeptideBuilder dialog by clicking the menu entry Build ⇒ Build Peptide.

Then enter the sequence ARND with the keyboard in the label field at the top (as an alternative you can also press the upper four amino acid buttons). This will create a polypeptide with the aminosequence (Alanin, Arginin, Asparagine, Aspartic acid).

Then press the Build button.This will enable the next step of the tutorial.