Which term describes a fatty substance including cholesterol, triglycerides, and phospholipids found in the body?

The term that describes a fatty substance including cholesterol, triglycerides, and phospholipids in the body is lipid. Lipids are a broad category of organic compounds that are hydrophobic, meaning they do not mix well with water. This characteristic allows them to serve various essential roles in the body, such as providing energy storage, forming cellular membranes, and acting as signaling molecules.

Cholesterol, a type of lipid, is crucial for synthesizing hormones and vitamin D, and it is also a component of cell membranes. Triglycerides are the main form of stored energy in the body and are made up of glycerol and three fatty acids. Phospholipids, which make up the lipid bilayer of cell membranes, have both hydrophobic and hydrophilic properties, allowing them to create a barrier that regulates what enters and exits the cell.

In contrast, carbohydrates serve as a primary energy source, proteins are vital for building and repairing tissues, and sugars are simple forms of carbohydrates that quickly provide energy. Therefore, the classification of cholesterol, triglycerides, and phospholipids as lipids is accurate and highlights their importance in biological functions.