Shown to left is a beta-strand composed of six residues, with the C-terminus to the right.

In order to put together a beta-sheet we need a second beta-strand.  The hydrogen bonds in a beta-sheet are always between strands.

  The six hydrogen bonds are perpendicular to the backbones and are nearly parallel to each other.  This becomes more apparent in the cartoon mode.

  Cartoon depicting the two beta-strands as arrows. The arrowhead always designates the C-terminus of the strand. These two strands are oriented in opposite directions or make up a antiparallel beta-sheet.  If the two strands run in the same direction, they are parallel.

  The beta-carbons of one strand are colored green, while those of the other strand are shown in magenta. Observe the highly regular pattern of side chains, alternating above and below the backbone ribbon.

  We are now looking at the actual side chains in this beta sheet.