Which of the following is the correct definition for protein? a. a form of carbohydrates which the body can't digest. b. an essential nutrient that makes up more than 50 percent of your body weight, important for growth, building and maintaining muscles, and supplying the body with energy, among other things. c. an essential nutrient that provides long-lasting energy, store vitamins, protects vital organs, and keeps the body warm. d. an essential nutrient that is the body's primary source of short- and long-term energy.

B. An essential nutrient that makes up more than 50 percent of your body weight, important for growth, building and maintaining muscles, and supplying the body with energy, among other things.

Explanation:

Protein is the most important of biological macromolecules, making up more than half the dry weight of a cell. It is present in every living being and has the most varied functions. Proteins may act as enzymes, catalyzing chemical reactions, may carry small molecules or ions; may be motor to assist movement in cells and tissues; participate in gene regulation, and is an essential nutrient that makes up more than 50% of body weight, important for the growth, building and maintenance of muscles and energy supply to the body, among other things.