In terms of the Toober model may be better to think of the space between marks as the peptide bond connecting the two amino acids. Even though it's not as correct as the visualization mentioned above, it will at least result in the right length for the Toober (since you wouldn't be representing the peptide bonds connecting 420-421 and 560-561). Just realize there's more to the protein than sidechains and peptide bonds, haha.
Of course, if you use your own materials, you can make it whatever length you want!
![Wink ;)](./images/smilies/icon_e_wink.gif)