Why can't catalysts make an unfavorable reaction favorable?Can anyone give me a relatively simple explanation for this?Thank you so much in advance!
Catalysts, as enzymes, only change the activation energy (the energy the compound needs to gain to transform into products), they don't change the Gibbs energy values of reactants nor products. Therefore, if the delta G of the reaction is positive, it'll still need free energy to complete. They make a reaction complete faster than in normal conditions, but don't change the actual possibility for that reaction to happen. In the human body, a lot of reactions of catabolism have a positive G value and these reactions needs to get energy from other coupled reactions that have a negative value, so the total value is still negative. Many of them use hydrolysis of ATP to provide that energy, as its hydrolysis is about -30 kJ/mol in physiological conditions. I don't know what class you're in to ask this question, so can't really know if this answer is too simple or complicated for u... sorry in advance! Jo?l
