Question 7.WKC.5: The following structure is a representation of histidine, an......

The following structure is a representation of histidine, an amino acid constituent of proteins. Only the connections between atoms are shown; multiple bonds are not indicated. Give the molecular formula of histidine, and complete the structure by showing where the multiple bonds and lone pairs are (red = O , gray = C , blue = N , ivory = H).

STRATEGY

Count the atoms of each element to find the formula. Then look at each atom in the structure to find what is needed for completion. Each carbon (gray) should have four bonds, each oxygen (red) should have two bonds and two lone pairs, and each nitrogen (blue) should have three bonds and one lone pair.