Organic compounds are, by definition, compounds of Carbon.And it
may be defined as hydrocarbons and derivatives.
Yes, Nitrogen is an integral and common bio-element found
primarily in proteins. Instead of the -C-C-C-C-C-C- of lipids, an
added N gives a great structural boost, as in the peptide chain
-C-C-N-C-C-N-C-C-N-C-C-N- etc.