The integration of novel nanomaterials with highly functional biological molecules has numerous advanced applications, includ- ing optoelectronics, biosensing, imaging, and energy harvesting. This review summarizes recent progress in understanding the mechanisms of energy transfer between semiconductor nanocrystal (so-called quantum dots [QDs]) and photosensitive proteins in heterostructures, such as hybrids of semiconductor nanocrystals with purple membranes containing bacteriorhodopsin (bR) or with photosynthetic reaction centers (RCs). Understanding of these mechanisms should enable prediction of the possible ways to improve the biological function of biomolecules by means of their assembling with QDs and develop novel functional materials with controlled photonic properties and applications. The possible mech- anisms of energy transfer from QDs to photochromic biomolecules are discussed and correlated with experimental data. The princi- ples of hybrid structures engineering, donor/acceptor parameters affecting both energy transfer effciency and biological function, and functionality of these hybrid structures are described. New nanobiohybrid materials are shown to have advanced implications for optoelectronics, photonics, and photovoltaics due to the ability of nanocomponents of these materials for effcient energy harvesting, conversion, and transfer of additional energy to Biosystems, thus making them working more effciently.