These motifs will greatly constrain the shape space that computational algorithms must search to successfully correlate primary amino acid sequence with the correct three-dimensional shapes. Once again the lexicon of motifs with their functional as well as structural correlations will play a critical role in solving this problem. The mass spectrometer will play a key role in identifying secondary modifications. If these functional complexes can be isolated, the mass spectrometer, coupled with a knowledge of all protein sequences that can be derived from the complete genomic sequence of the organism, will serve as a powerful tool for identifying all the components of complex molecular machines. The third type of biological information arises from complex biological systems and networks.
Systems information is four dimensional because it varies with time.
For example, the human brain has 1,012 neurons making approximately 1,015 connections. From this network arise systems properties such as memory, consciousness, and the ability to learn. To study most biological systems, three issues need to be stressed. First, most biological systems are too complex to study directly, therefore they must be divided into tractable subsystems whose properties in part reflect those of the system. These subsystems must be sufficiently small to analyze all their elements and connections.