i got this homework where it tells me to look for food products and fill this in

-Biomolecles present and which are the most abundant
-the basic unit of each biomolecule present
-the elements present in the basic unit of each biomolecule

i dont know what the hell is the basic unit… can someone put examples of what should be on each???? doesnt matter if it is not correct u can put protein doesnt matter what the answer might be just to know what is suposed to be what. thx