Question

Cells use the hydrolysis of adenosine triphosphate, abbreviated as ATP, as a source of energy. Symbolically, this reaction can be written asATP(aq)+H2O(l)⟶ADP(aq)+H2PO−4 (aq)where ADP represents adenosine diphosphate. For this reaction, ΔG∘=−30.5kJ/mol.a. Calculate K at 25∘C .b. If all the free energy from the metabolism of glucoseC6H12O6(s)+6O2(g)⟶6CO2(g)+6H2O(l)goes into forming ATP from ADP, how many ATP molecules can be produced for every molecule of glucose?

Answer 1

Answer:

Step-by-step explanation:

From the given information:

ΔG° = -30.5 kJ/mol

By applying the following equation to calculate the value of K.

ΔG° =-RT㏑K

making ㏑ K  the subject of the formula:

$\mathtt{ In \ K} = \dfrac{\Delta G^0}{-RT}$

where;

Temperature at 25° C = (25 + 273)K

= 298K

R = 8.3145 J/mol.K (gas cosntant)

$\mathtt{ In \ K} = \dfrac{-30.5 \times 10^{3}\ J /mol} {-(8.3145 \ J/mol. K \times 298 \ K}$

$\mathtt{ In \ K} = \dfrac{-30.5 \times 10^{3}\ J /mol} {-2477.721 J/mol }$

㏑K = 12.309

$K = e^{12.309}$

K = 221682.17

K = 2.22 × 10⁵

b) The reaction for the metabolism of glucose is given as:

$C_6H_{12} O_6 + 6O_{2(g)} \to + 6CO_{2(g)} + 6H_2O_{(l)}$

From the above expression, let calculate the Gibbs free energy by using the formula:

$\Delta G^0_{rx n }= \Delta G^0_{product}- \Delta G^0_{reactant}$

$\Delta G^0_{rx n }= [6 \times \Delta G^0_{f}(CO_2) + 6 \times \Delta G^0_{f}(H_2O)] - [1 \times \Delta G^0_{f}(C_6H_{12}O_6) + 6 \times \Delta G^0_{f}(O_2)]$

At standard conditions;

The values of corresponding compounds are substituted into the equation above:

Thus,

$\Delta G^0_{rx n }= [6 \times (-394) + 6 \times (-237)] - [1 \times (-911) + 6 \times (0)] \ kJ/mol$

$\Delta G^0_{rx n }= [-2364-1422] - [-911+0] \ kJ/mol$

$\Delta G^0_{rx n }= -3786 +911 \ kJ/mol$

$\Delta G^0_{rx n }= -2875 \ kJ/mol$

$\Delta G^0_{rx n }= -2875000 \ J/mol$

Now, the no of ATP molecules generated = $\dfrac{\Delta G^0 \text{of metabolism for glucose}}{\Delta G^0 \text{of hydrolysis for ATP}}$

= (-2875000 J/mol ) / -30500 J/mol

= 94.26

≅ 94 ATP molecules generated