Communication between cells in multi-cellular organisms, such as animals, humans and plants, is essential for coordinating the organismic activities of fertilisation, growth, survival and reproduction. This biochemical communication between trillions of cells in organisms can be more complex than the internet. This paper develops a CMOS circuit model of signal reception and signal transduction within a cell in response to extracellular molecular signals. A micro-sequenced model has been developed where the signal transduction steps are clocked by circadian time intervals. The model converts the chemical signalling pathway into a CMOS multi-step logical transformation cascade transducing a received signal molecule into an activated cellular protein response. This modelling technique leads to understanding cellular malfunctions (diseases) in the form of logical (electrical) faults in a circuit.