is shown as
		Note that most protein structures do not show H's The above pictures represent the same structure. The one on the left is unusual, but more complete. The one on the right is what you will find in 98% of published structures. You must mentally fill in the hydrogen...

Amide bonds are resonance hybrids

Note that the result is a partial double bond between C and N, and the placement of partial negative charge on oxygen and partial positive charge on nitrogen (and out onto the hydrogen as well, there is a third resonance structure to do this!).

Which is also explained by sp² hybridization