Which term is used to denote carbon-containing organic material dissolved in water?

• A. Dissolved Organic Carbon
• B. Dissolved Organic Nitrogen
• C. Energy
• D. Endothermic

Answer: (A)

Understanding the term for carbon-containing organic material dissolved in water. This material is called dissolved organic carbon. It spans a wide range of compounds—from small molecules like sugars and amino acids to larger substances such as humic substances—and represents a major pool of carbon in aquatic systems that microbes can use. It’s measured as carbon content, typically in milligrams of carbon per liter.

Dissolved Organic Nitrogen refers to organic molecules that contain nitrogen, not specifically carbon-containing material as a whole. Energy is a property describing the capacity to do work, not a type of dissolved material. Endothermic describes a heat-absorption process, not a dissolved substance. Therefore, the term that denotes carbon-containing organic material dissolved in water is dissolved organic carbon.