For reaction A --> B (delta G°′ = −10 kJ/mole), do you think this reaction is spontaneous under physiological (or cellular) conditions? Why or why not?

Answer 1

You are given a gibbs free energy value at standard conditions (25 degrees Celsius, all concentrations at 1 molar, and a pressure of 1 atm). Your body is far from standard conditions (36 to 37 Celcius, not 1 molar concentrations of ions). You need to convert ΔG^o standard conditions to non-standard conditions. This is usually done with the formula below.

ΔG = ΔG^o + RTlnQ

You know ΔG^o, R, and T. However, you need more information about what reaction in the body you are referring to to get a value of Q.