Thermodynamic constraints on biomass and product yields

Metabolism is subjected to the absolute thermodynamic constraint of AfCgrowth dissipation and to the existing biochemical pathways. However, it is 

This corresponds to the usual oxido-reductive growth some oxygen is consumed, COj and heat are produced. The limit case is obtained for foj/G = 0, which corresponds to pure anaerobic growth. 

Oxygen is produced since the point is to the right of the line Ko /o = 0, but is thermodynamically possible since it is to the left of the constraint AfG = 0. Some heat is still produced, as well as CO2 (point to the left of the limit lines). 

Oxygen is produced and heat is consumed. The growth reaction is still spontaneous since some Gibbs energy is dissipated. 

Growth is not possible above the limit line corresponding to A G = 0. The limit case is obtained for ArG = 0 which corresponds to thermodynamic equilibrium, which is by far not the usual state of a biological system. Growth is possible since the point is below the line ArG = 0. However, the point is above the line Yco /g 0, which means that CO2 is taken-up from the environment. Similarly, heat is absorbed (Ar// 0) and oxygen is produced. 

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