The four types of organic compounds are carbohydrates, lipids, proteins and nucleic acids. Organic molecules contain the elements carbon and hydrogen, and they are found and made in living things.
Carbohydrates are sugars such as glucose, sucrose and starch. Lipids are fats and usually do not like water, so they form part of the cell membrane to act as barriers to a watery environment. Proteins have a variety of functions and are typically large molecules. They act as structural components, are significant in cell-to-cell communication, and speed up or catalyze reactions within the cells. Nucleic acids carry the genetic material to make new organisms. Two types of nucleic acids exist in organisms: DNA and RNA.