Before revision:  The MAPK cascade (Raf-MEK-ERK pathway) is used as an illustrative example which demon- strates how the computational modularity provided by the bond graph approach avoids the errors associated with assuming irreversible Michaelis-Menten kinetics and emphasises the necessity for a power supply to support behavioural modularity in signalling networks .
After revision:  The MAPK cascade (Raf-MEK-ERK pathway) is used as an illustrative example .