The structural work has, however, shown that there is a close relationship between the bacterial reaction centre and the oxygen-evolving protein complex in higher plants, so that the structure determined can be used also to increase our understanding of photosynthesis in general. The structural picture agrees well with the order of the electron transfer steps established earlier by more indirect methods. The detailed structure now forms the basis for more precise attempts to explain theoretically the course of the individual chemical steps. The structural determination rewarded has considerable chemical importance far beyond the field of photosynthesis. Many central biological functions in addition to photosynthesis and cell respiration are associated with membrane-bound proteins.
Examples are transport of chemical substances between cells, hormone action and nerve impulses.
The structure of the reaction centre has clarified the principles governing the three dimensional structure of proteins spanning biological membranes, e.g. ion pumps and other transport proteins. Thanks to the method of crystallization developed by Hartmut Michel the prospects of obtaining detailed structural information also for other membrane proteins have improved.