All Questions
Tagged with free-energy biochemistry
10
questions
2
votes
1
answer
685
views
Why can one set the Gibbs free energy change to 0 when calculating the standard free energy change?
I am trying to understand the following equation:
$$\Delta G = \Delta G^{\circ} + RT \ln\left(\frac{[C][D]}{[A][B]}\right)$$
for a reversible reaction with reactants A and B and products C and D.
The ...
- 23
6
votes
0
answers
206
views
Why is the reverse aldol cleavage of fructose 1,6-bisphosphate highly endergonic under standard conditions?
I have another question similar to this one. I just don't have intuition for why reactions are thermodynamically favorable or unfavorable and I'd like to build it. This time I'd like to ask about ...
- 289
4
votes
1
answer
2k
views
Why is the formation of a peptide bond not spontaneous?
Why is the formation of a peptide bond from a carboxylic acid and amine not spontaneous?
I'm not looking for the free energy calculation; I have it from several sources. I'm just asking for an ...
- 289
1
vote
2
answers
134
views
How does work from other sources affect Gibbs free energy of the system?
In most physical chemistry textbooks, Gibbs free energy is given like this:
$$\Delta_\mathrm rG = \Delta_\mathrm rG^\circ + RT\ln Q\tag{1}$$
and Gibbs free energy is part of this three-way ...
- 323
6
votes
1
answer
206
views
Biomolecular energy functions and entropy
From what I've been reading, it seems that entropy (rather than enthalpy) is the biggest driver of protein folding (especially the burying of hydrophobic residues). However, popular energy functions ...
- 163
3
votes
2
answers
1k
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Why energy of some intermediates of glycolysis increases?
It is possible that I do not understand the concept of energy, but according to the diagram in my book, the energy between steps 4 and 5 and between 6 and 8 increases. How is this possible? Also, as ...
- 31
10
votes
6
answers
81k
views
What's the difference between ΔG° and ΔG°'?
In biochemistry contexts, one often sees $\Delta G^{\circ\prime}$ ("delta G naught prime"), rather than the normal standard free energy change $\Delta G^{\circ}$ ("delta G naught").
What's the ...
- 4,982
16
votes
2
answers
8k
views
Is the Gibbs standard free energy always constant?
I am a biochemistry student and we are learning about thermodynamics. Is the Gibbs standard free energy for a reaction always constant? The equation below suggests that it changes with temperature:
$$...
- 455
2
votes
0
answers
414
views
Delta G values for Pyruvate--> Alanine vs. Oxaloacetate -> Aspartate ->Asparagine
What are the delta G values for the mammalian (human) biosynthesis of alanine from pyruvate, and for the conversion of oxaloacetate to asparagine? (assuming no particular cellular restriction or other ...
1
vote
0
answers
158
views
Why are non-polar hydrogens neglected in computational protein-drug binding studies?
Why are (non-polar) hydrogen atoms generally neglected in a protein-ligand (or drug) binding energy calculation? They do have charge and mass. Doesn't that affect the free energy calculation?
The ...
- 517