Beta decay is a consequence of the weak force, which is characterized by relatively lengthy decay times. Nucleons are composed of up or down quarks, and the weak force allows a quark to change type by the exchange of a W boson and the creation of an electron/antineutrino or positron/neutrino pair.
Most procaryotes contain some sort of a polysaccharide layer outside of the cell wall polymer. In a general sense, this layer is called a capsule. A true capsule is a discrete detectable layer of polysaccharides deposited outside the cell wall.
Cell wall: The cell wall is a rigid layer that surrounds the plant cells. Plant cell walls are primarily made up of cellulose. It is located outside the cell membrane whose main function is to provide rigidity, strength, protection against mechanical stress and infection.