It looks like you're asking about the four major classes of organic compounds found in living organisms. You've already named two: proteins and carbohydrates. Let's complete the list:

The four major classes of organic compounds found in living organisms are:

1. Carbohydrates: These are sugars and starches, composed of carbon, hydrogen, and oxygen. They are a primary source of energy for living things.

2. Lipids: These are fats, oils, and waxes. They are important for energy storage, insulation, and cell membrane structure.

3. Proteins: These are complex molecules made up of amino acids. They are involved in a vast array of functions, including structural support, enzymes, hormones, and antibodies.

4. Nucleic acids: These are DNA and RNA, responsible for storing and transmitting genetic information.

Let me know if you'd like to learn more about any of these classes of organic compounds!