Organic compounds contain carbon, usually in combination with hydrogen, oxygen, nitrogen, or sulfur. Organic compounds were first associated only with plants and animals. However, a great number of organic compounds have now been prepared that do not occur in nature. | Organic compounds contain carbon, usually in combination with hydrogen, oxygen, nitrogen, or sulfur. Organic compounds were first associated only with plants and animals. However, a great number of organic compounds have now been prepared that do not occur in nature. |