protein

noun3

1. •
   Any of numerous large, complex naturally-produced molecules composed of one or more long chains of amino acids, in which the amino acid groups are held together by peptide bonds.

   • Proteins carry out the bulk of cellular functions, including relaying signals, providing structural support, and accelerating biochemical reactions. — 2010
2. •
   One of three major classes of food or source of food energy (4 kcal/gram) abundant in animal-derived foods (meat) and some vegetables, such as legumes.
3. •
   A food rich in protein, often a meat or meat substitute.

   • The preparation style should be the same for both proteins so that the side dishes compliment the meal. — 2015