Determining the orientation and conformation of an adsorbed biomolecule at an inorganic interface remains a grand challenge in studies of interest to materials science, medicine and biotechnology. The theme of this talk will be to share recent advances from our group in fundamental science and engineering of interfacial phenomena of complex peptides. Through the lens of understanding structure-function relationships and making predictions of adsorbed-peptide structure, this talk will also introduce a suite of computational tools that can be used to study these complex systems. The first part of this talk will highlight how we are using simulations to understand the dominant driving forces that lead to unique orientation and conformation of peptides at the bio/nano interface with an illustration of how the surface/peptide interface strongly dictates the dominant contributions to binding energetics. I will also discuss the challenge of accurately predicting biomolecule structure at interfaces and how a marriage of simulation and sparse experimental data can provide deep insight. Following this I will share several examples related to the formation of biosilica in two systems: peptides based on marine diatoms, and the recognition domain of the salivary protein statherin.