Question

You are a metabolic engineer trying to engineer a novel metabolic pathway to produce an important chemical. One of the required steps is thermodynamically unfavorable (Gibbs free energy > 0). How could you engineer the pathway to overcome this barrier and ensure flux from substrate to product?

Answer 1

In Order to do this we will have to comeback to the basic equation of Change in Gibbs' energy which is given by

Now for a reaction to be favorable we need to have dG <0

So

dG <0

dH -T*dS <0

So now we can approach the problem in the following way

1. We will have to Raise the temperature ('T") to an extent where the quantity such dH -T*dS is negative

(No entropy (S) and Enthalpy (H)) both are functions of temperature so one will have to do do it by trial and error and all variables are functions of temperature and obtain the desired value of temperature

In order to begin we will require the value of Temperature for this set dG =0

Hence we will have

dH -T*dS =0

T = dH/dS

Hence we can start with a value of Temperature greater than above value to beign our calculatioon and obtain the final results