Question

The four fundamental types of organic molecules are nucleic acids, proteins, lipids, and ________.

Answer 1

Answer:

Carbohydrates

Explanation:

Organic compounds  are made of four fundamental type organic molecules which also called biological macro molecules. These fundamental types molecules are

1. Nucleic Acids

2. Proteins

3. Lipids

4. Carbohydrates

Macro molecules are made of single unit called monomer and these monomer are joined covalent  bonds to form larger polymers.

Answer 2

The other of the four organic molecules is carbohydrates. 
All four of them are:
Nucleic Acids (DNA and RNA stuff)
Proteins
Lipids
& Carbohydrates