Example Question #1 : Lipids
Plants often have a waxy covering on the outside of their leaves to prevent water loss. This waxy covering probably contains mostly which organic compound?
A nucleic acid
Major lipid groups include fats, steroids, and waxes. Because the question references a "waxy covering," we know that the plant covering must be composed of lipids.
Example Question #2 : Lipids
Which organic compound serves as stored energy for living things?
Lipids make up the bulk of fat in animal tissues and thus stores energy.
Example Question #3 : Lipids
Which of the following macromolecules are composed of long chains of amino acids?
By process of elimination, lipids and fats cannot be the correct answer-they are synonymous (lipids are also known as fats). Carbohydrates, eg sugars and starches are composed only of carbon, hydrogen, and oxygen. Nucleic acids contribute to DNA and RNA structure and function. The correct answer is proteins, made of long chains of amino acids-amino acids are sometimes called the "building blocks" of proteins.