What type of compound consists of three fatty acids and one glycerol molecule?

The correct answer is triglyceride. Triglycerides are a type of lipid and are composed of three fatty acid molecules bonded to a single glycerol molecule. This structure allows for the storage of energy in a compact form, as fats and oils, which can be utilized by the body when energy is needed. The glycerol acts as a backbone to which the fatty acids are attached, and the saturation level of the fatty acids (whether they contain double bonds or are saturated with hydrogen) can vary, influencing the properties of the triglyceride.

Phospholipids, though similar in structure, consist of two fatty acids, a glycerol, and a phosphate group. They play a crucial role in forming cell membranes but do not fit the definition of having three fatty acids. Sterols, such as cholesterol, have a completely different structure and do not comprise fatty acids or glycerol. Cholesterol, in particular, is a type of sterol that is essential for cell membrane structure and hormone production, but it does not contain the fatty acid composition characteristic of triglycerides. Therefore, the unique structure of triglycerides, defined by having three fatty acids and one glycerol, makes it the accurate answer.