The conversion of glucose into lactic acid drives the phosphorylation of 2 moles of ADP to ATP and has a standard free energy of -135 kJ/mol.
C6H12O6 + 2 HPO4 + 2 ADP + 2 H+ -->
2CH3CH(OH)COOH + 2 ATP + 2H20
What is the standard free energy for the conversion of glucose into lactic acid:
C6H12O6(aq) --> 2 CH3CH(OH)COOH(aq)
The answer will be in units of kJ.
From what I've read in the textbook, I need to take the formula above and add it together with the value I get from ATP hydrolysis, which is (-30.5). I am stumped what to do next because I know I have to take the number of moles into account, but don't know how to since the book does not cover examples with stoichiometric coefficients.
To calculate the standard free energy change (ΔG°) for the conversion of glucose into lactic acid, you need to consider the stoichiometric coefficients. In this reaction, the stoichiometric coefficient of glucose is 1, while the stoichiometric coefficient of lactic acid is 2.
The standard free energy change (ΔG°) for a reaction is related to the standard free energy change (ΔG°) per mole of reactant by the equation:
ΔG° = nΔG°m,
where n is the stoichiometric coefficient.
In this case, the equation for the conversion of glucose into lactic acid with stoichiometric coefficients is:
C6H12O6(aq) --> 2 CH3CH(OH)COOH(aq)
So, the standard free energy change (ΔG°) for the conversion of glucose into lactic acid is given by:
ΔG° = 2 ΔG°m
Since the standard free energy change (ΔG°m) for the conversion of glucose into lactic acid is -135 kJ/mol, the standard free energy change (ΔG°) for the overall reaction is:
ΔG° = 2(-135 kJ/mol) = -270 kJ
Therefore, the standard free energy change for the conversion of glucose into lactic acid is -270 kJ.
To calculate the standard free energy change for the conversion of glucose into lactic acid, you need to consider the stoichiometric coefficients and the standard free energy values of each compound involved.
First, let's consider the equation for the conversion of glucose into lactic acid:
C6H12O6(aq) → 2 CH3CH(OH)COOH(aq)
The standard free energy change for this reaction can be calculated using the formula:
ΔG° = ΣΔG°f(products) - ΣΔG°f(reactants)
where ΔG° is the standard free energy change, ΣΔG°f(products) is the sum of standard free energy of formation for the products, and ΣΔG°f(reactants) is the sum of standard free energy of formation for the reactants.
Now, let's calculate the standard free energy change step by step:
1. Determine the standard free energy change for each compound involved:
- For glucose (C6H12O6(aq)), you need to find the standard free energy of formation (ΔG°f). This value is not given directly, but you can look it up in a table of standard free energy of formation.
- For lactic acid (CH3CH(OH)COOH(aq)), you also need to find the standard free energy of formation.
- Since the equation involves the conversion of only one mole of glucose into two moles of lactic acid, you will need to multiply the standard free energy of formation of lactic acid by 2.
2. Calculate the standard free energy change for the conversion of glucose into lactic acid:
- Subtract the sum of the standard free energy of formation for the reactants (glucose) from the sum of the standard free energy of formation for the products (lactic acid).
- Be sure to multiply the standard free energy of formation of lactic acid by 2 to account for the stoichiometric coefficient.
3. Finally, you need to add the ATP hydrolysis value (-30.5 kJ/mol) to the calculated value from step 2 to get the total standard free energy change.
Remember to convert the units as necessary to ensure consistency.
I hope this helps!