ANS: protiens
1.) Proteins are essential parts of organisms and participate in every process within cells.
2.) . They also have structural or mechanical functions, such as actin and myosin in muscle, and the proteins in the cytoskeleton, which maintains cell shape.
3.) Proteins are also important in cell signalling, immune responses, cell adhesion, and the cell cycle
4.) Many proteins are enzymes that catalyse biochemical reactions, and are vital for metabolism..
5.)Proteins are also necessary in animals' diets, since they cannot synthesise all the amino acids and must obtain essential amino acids from food. During digestion, animals break down ingested protein into free amino acids that are then used in metabolism.