Which type of protein is missing one or more of the essential amino acids?

The type of protein that is missing one or more essential amino acids is called an incomplete protein. Essential amino acids are those that the body cannot synthesize on its own and must be obtained through diet. Incomplete proteins typically come from plant sources, such as legumes, grains, and nuts. These proteins may lack one or more of the essential amino acids needed for the body’s full protein synthesis.

In contrast, complete proteins contain all essential amino acids in adequate amounts and are generally found in animal products like meat, fish, dairy, and eggs. Complementary proteins refer to the practice of combining two incomplete protein sources to make a complete protein, like rice and beans. Simple proteins are a term that typically refers to proteins made from amino acids that do not contain complex structures or side chains but does not describe the presence or absence of essential amino acids. Thus, the most accurate choice for a protein lacking essential amino acids is indeed an incomplete protein.