Acritical reaction in the production of energy to do work or drive chemical reactions in biological systems is the hydrolysis of adenosine triphosphate, atp, to adenosine diphosphate, adp, as described by
atp(aq) +h2o (l) > adp(aq) +hpo4 (negative two overall charge) (aq).
for which δg°rxn = –30.5 kj/mol at 37.0 °c and ph 7.0. calculate the value of δgrxn in a biological cell in which [atp] = 5.0 mm, [adp] = 0.30 mm, and [hpo4^2–] = 5.0 mm.

a. what is the delta g rxn in kj/mol?
b. is the hydrolysis of atp spontaneous under these conditions?

Answer :

(a) The value of is -51.4 kJ/mol

(b) Yes, the hydrolysis of ATP spontaneous under these conditions.

Explanation :

First we have to calculate the reaction quotient.

Reaction quotient (Q) : It is defined as the measurement of the relative amounts of products and reactants present during a reaction at a particular time.

The given balanced chemical reaction is,

The expression for reaction quotient will be :

In this expression, only gaseous or aqueous states are includes and pure liquid or solid states are omitted.

Given:

= 5.0 mM

= 0.30 mM

= 5.0 mM

Now put all the given values in this expression, we get

Now we have to calculate the value of .

The formula used for is:

   ............(1)

where,

= Gibbs free energy for the reaction  = ?

=  standard Gibbs free energy  = -30.5 kJ/mol

R = gas constant =

T = temperature =

Q = reaction quotient =

Now put all the given values in the above formula 1, we get:

Therefore, the value of is -51.4 kJ/mol

Gibbs free energy : It is defined as the amount of energy that is available to do useful work.

A reaction to be spontaneous when

A reaction to be non-spontaneous when

As the value of is less than 0. So, the reaction will be spontaneous.

Yes, the hydrolysis of ATP spontaneous under these conditions.