  We consider a natural class of reaction networks which consist of reactions
where either two species can inactivate each other (i.e., sequestration), or
some species can be transformed into another (i.e., transmutation), in a way
that gives rise to a feedback cycle. We completely characterize the capacity of
multistationarity of these networks. This is especially interesting because
such networks provide simple examples of "atoms of multistationarity", i.e.,
minimal networks that can give rise to multiple positive steady states
