[proh-teen, -tee-in] 
| 1. | Biochemistry. any of numerous, highly varied organic molecules constituting a large portion of the mass of every life form and necessary in the diet of all animals and other nonphotosynthesizing organisms, composed of 20 or more amino acids linked in a genetically controlled linear sequence into one or more long polypeptide chains, the final shape and other properties of each protein being determined by the side chains of the amino acids and their chemical attachments: proteins include such specialized forms as collagen for supportive tissue, hemoglobin for transport, antibodies for immune defense, and enzymes for metabolism. |
| 2. | the plant or animal tissue rich in such molecules, considered as a food source supplying essential amino acids to the body. |
| 3. | (formerly) a substance thought to be the essential nitrogenous component of all organic bodies. |
| 4. | Biochemistry. of the nature of or containing protein. |
[proh-teed, -tee-id] . [proh-tee-ney-shuh
s, -tee-i-ney-] , pro⋅tein⋅ic, pro⋅tei⋅nous, adjective | pro·tein (prō'tēn', -tē-ĭn) n. Any of a group of complex organic macromolecules that contain carbon, hydrogen, oxygen, nitrogen, and usually sulfur and are composed of one or more chains of amino acids. Proteins are fundamental components of all living cells and include many substances, such as enzymes, hormones, and antibodies, that are necessary for the proper functioning of an organism. They are essential in the diet of animals for the growth and repair of tissue and can be obtained from foods such as meat, fish, eggs, milk, and legumes. [French protéine, from Late Greek prōteios, of the first quality, from Greek prōtos, first; see per1 in Indo-European roots.] pro'tein·a'ceous (prōt'n-ā'shəs, prō'tē-nā'-), pro·tein'ic (prō-tē'nĭk), pro·tein'ous (prō-tē'nəs) adj. |
protein pro·tein (prō'tēn', -tē-ĭn)
n.
Any of a group of complex organic macromolecules that contain carbon, hydrogen, oxygen, nitrogen, and usually sulfur and are composed of chains of alpha-amino acids. Proteins are fundamental components of all living cells and include many substances, such as enzymes, hormones, and antibodies, that are necessary to the functioning of an organism. They are essential in the diet of animals for the growth and repair of tissue and can be obtained from foods such as meat, fish, eggs, milk, and legumes.