Although biomolecules evolved to function in the cell, most biochemical and biophysical studies have been carried out in vitro. A combination of in vitro, in-cell, and in vivo studies will highlight how steric and non-steric interactions modulate protein folding and protein-RNA interactions. I will introduce a customized pipeline that combines meganuclease mediated transformation with fluorescence-detected temperature-jump microscopy to image fast dynamics of biomolecules in living zebrafish with single-cell resolution. To interpret in vivo and in-cell results, an in vitro systematic series of solvation environments will distinguish contributions from non-steric and steric interactions to stability, compactness, and kinetics. Our results demonstrate that different cellular environments of different tissues contribute to different protein stability and kinetic phenotypes