Noun
secondary structure (countable and uncountable, plural secondary structures)
(biochemistry) The general three-dimensional structure of a biopolymer such as DNA or a protein.
Secondary structure can be formally defined by the pattern of hydrogen bonds of the protein (such as alpha helices and beta sheets ) that are observed in an atomic-resolution structure. Source: Internet
Secondary structure is concerned with local morphology (morphology being the study of structure). Source: Internet