Molecular Cell Biology: A Quick Introduction for non-Biologists

One may view cell life as a collection of “wireless networks” of interactions among proteins, RNA, DNA, and small molecules involved in signaling and energy transfer. These networks process environmental signals, induce appropriate cellular responses, and sequence internal events such as gene expression, thus allowing cells and entire organisms to perform their basic functions. These control and communication networks can be relatively simple, such as the two-component systems found mainly in bacteria, which are cascades connecting sensors (proteins in the cell membrane, which detect outside signals) to actuators (typically transcription factors, which direct the expression of a gene). Or they may be incredibly sophisticated, as in higher organisms, involving multiple signal transduction pathways in which information is relayed among enzymes through chemical reactions (for instance, phosphorylation).