Structure and Functions of Contractile Proteins focuses on the analysis of problems on the structure and functions of contractile proteins in which substantial progress has been achieved. The book first offers information on the protein constitution of myofibrils and myosin, including adenosinetriphosphatase activity, reaction with actin, and myosin molecule. The text also ponders on the polymerization of actin, tropomyosin, and the theory of contraction. Discussions focus on model experiments and molecular basis of contraction; structural interrelations of muscle proteins; features of the process of polymerization of actin; and size of the actin molecule. The text elaborates on the contractile proteins of the elementary motor structures of cells, as well as the chemical composition and physicochemical and enzymic properties of flagella and cilia; achromatin apparatus and movement of chromosomes; and structure of the flagella and cilia. Motor apparatus of bacteriophage and features of the movement of protoplasm and the mechanism of permeability are also discussed. The manuscript is a reliable source of data for readers interested in the structure and functions of contractile proteins.