Trewhella is a biophysicist who uses physical methods to study how bio-molecules interact and communicate in order to carry out functions that involve multiple molecular actors working in concert. One frequently used biophysical tool is the small-angle scattering of x-rays and neutrons in order to probe the solution conformations of proteins and the complexes they form. Trewhella’s early work focused on how intracellular “second messengers,” such as Ca²⁺ and cAMP, relay extracellular signals. More recently she has turned to studies of the two-component signaling mechanisms that are used by bacteria to respond to environmental signals. Trewhella also works with leading crystallographic and NMR labs on methodology development for combining low resolution solution scattering data with high resolution structures to develop a more complete picture of the structure and dynamics of biomolecules and the complexes they form in order to carry out their highly specialized functions.