any of a large group of nitrogenous organic compounds that are essential constituents of living cells; consist of polymers of amino acids; essential in the diet of animals for growth and for repair of tissues; can be obtained from meat and eggs and milk and legumes

one of the proteins into which actomyosin can be split; can exist in either a globular or a fibrous form

a simple water-soluble protein found in many animal tissues and liquids

a family of proteins found in blood and milk and muscle and in plant seed

a colorless protein obtained by removing heme from hemoglobin; the oxygen carrying compound in red blood cells

a simple protein found in the seeds of cereals