The four fundamental types of organic molecules are nucleic acids, carbohydrates, lipids, and
which term best completes the sentence?
phosphates
nitrates
proteins
sulfates

The answer is "proteins". The four fundamental types of organic molecules are nucleic acids, carbohydrates, lipids, and proteins.

Explanation:

All these molecules contain carbon, hydrogen and oxygen.

Carbohydrates are the primary source of chemical energy for living systems. Lipids are hydrophobic molecules that store energy and are important structural components. They include fats and oils, phospholipids, glycolipids, waxes, cholesterol and other steroids.Proteins are very large molecules composed of long chains of amino acids.Nucleic acids are complex molecules formed by a phosphate group, a five-carbon sugar and a nitrogen base. They are the structural blocks of deoxyribonucleic acids (DNA) and ribonucleic acids (RNA), which transmit and translate genetic information. They also play central roles in energy exchanges that accompany chemical reactions within living systems.