Change in free energy can occur in two ways of a molecules. either free energy is released/ consumed in the bond(enthalpy) during rexn or energy is used as vibrating molecules here and there(entropy).
How can we benefit from the energy we get by ATP Hydrolysis? By phosphorylation or by using the released energy (i think it is called gibbs energy) or both ways?
I have a question: in a mitochondrian, if the matrix ATP concentration is high, and the intermembrane space proton concentration is too low to generate sufficient proton-motive force, then A) ATP synthase will hydrolyze ATP and pump protons into the matrix B) ATP synthase will increase the rate of ATP synthesis C) ATP synthase will hydrolyze ATP and pump protons into the intermembrane space D) ATP synthase will stop working
May be a bit late, but I suggest it would be C), because the ATP-Synthase can also work in reverse. If there is not enough Protons in the intermembrane space, there is no driving force of Protons to fuel ATP-Synthase to generate ATP. And if the ATP concentration of ATP in the matrix vs the intermembrane space is low (i.e. less ATP outside the matrix than inside), ATP-synthase would 'push out' ATP by hydrolizing it and therefore also increasing the proton concentration i the intermembrane space.
What I always find confusing are: 1.) If energy is REQUIRED in some reactions, shouldn't ATP be written on the reactant side since we could be reading it as, for example the hydrolysis reaction, NEEDING ATP and H20 to make ADP and a free phosphate group? 2.) If a reaction is endergonic, meaning the reaction is non-spontaneous, shouldn't ATP be in somewhere in the equation to drive the reaction forward?
you said add but its minus... i thought it sum of ( n moles times delta g of products) - sum of (n moles times delta g of reactants) equals delta g of reaction
Gibbs free energy is really confusing :S I understand the idea of spontanaeity and feasibility and the magnitude of the result. I believe that Gibbs free energy is total energy in a system that can be used to do work but... how does chemical reaction produce more energy than dH - which is the heat?? LIke when you use a calorimeter to find dH - the energy released by reaction does work to heat to surroudnings and we can use heat capacity etc to measure that, and this heat can be utilised. So how does gibbs free energy apply to a chemical reaction and hydrolysis of ATP? I am just confused about what this energy. other than dH really is... and when do we use it/observe it. I think I must be totally missing the point but could someone shed some light on this topic :S
The change in Gibbs free energy for a particular chemical transformation from reactants to products is defined as: dG = dH - TdS where T is in Kelvins. I think this thermodynamic state function (independent of path) gives information about the overall spontaneity of the reaction by considering ONLY the properties of the system (a reaction mixture for example) rather than both the system and the surroundings. Equivalently, dG = -TdS(total or universe) = -T(dSsystem + dS(surroundings). But it is often difficult to assess spontaneity by considering both the system and the surroundings. This is why dG it is so useful. If you think about it, the term dH (also q, the heat of a reaction released or absorbed at constant pressure) tells you how much heat is absorbed or released from the system and because dS = dq/T (infinitesimal change in q changes S as dq/T), energy transfers through heat (utilization of or promoting the random motion of atoms) are directly linked to changes in entropy which is, by definition, a measure of total disorder (or the measure of how many ways a system can be described while keeping the total energy constant). Note that heat is not a property of a system, rather, it is simply a WAY of transferring energy. For example, if the reaction is exothermic and released heat (dH < 0), heat flows INTO the surroundings and thus increases the entropy in the surroundings. Likewise, an endothermic reaction absorbs heat from the surroundings and DECREASES the entropy of the surroundings. Consider the second law of thermodynamics: everything tends to disorder, or, equivalently, the change in entropy of the universe is ALWAYS positive in a spontaneous process. So, it would be expected that dS(total) = dS(system) + dS(surroundings) > 0. Think about a bag of marbles: if you dump the whole thing, what happens? Your marbles roll around everywhere, it creates more disorder, it has the natural TENDENCY to occur. This is just the definition of a spontaneous process! What happens if you take an ice cube out of your freezer and put it on a table at room temperature? It melts right? It has a spontaneous tendency to do so. Entropy covers the dispersal of both energy AND matter. Now, back to our consideration of the Gibbs free energy. I mentioned above that it is convenient in that it allows us to assess whether or not a process is spontaneous only by considering the state functions of the system alone. Why is this? Well, as I said, a spontaneous change is one where theTOTAL entropy is increased.I also said that heat (NOT work) is a way of transferring energy that results in entropy changes. Finally, because deltaH = q at constant pressure, we can derive the following: We know that dS(surroundings) = - dq(system) / T (If the system absorbs heat, dqsys > 0 and dS < 0 and vice-versa) But we can also say that: dS (surroundings) = - dH(system) / T right? Now we're getting somewhere because we've ALREADY defined the entropy of the surroundings in terms of the change in enthalpy of the system. The total entropy equation becomes: dS (total) = dS (system) - (dH(system)/T) Multiply BOTH sides by -T, -TdS(total) = dH - TdS Look familiar? It should! Because, dG = dH - TdS, and -TdS (total) Why is this significant? My rambling above should be useful in that delta G depends not on the energy of a system but of the impact a heat transfer has on the surroundings! So, in considering ATP hydrolysis, delta G, also considered to be the maximum non-expansion work that can be done, is negative and thus can be used to drive endergonic chemical processes such as active transport in and out of cells, muscle contraction, and many more non-spontaneous metabolic reactions. By adding a highly negative delta G to a positive one with a smaller magnitude, the OVERALL free energy change can be negative and thus, be spontaneous. I think that's why we usually refer to ATP as "energy currency" because it supplies the energy required to drive certain biological reactions. Everything I stated above are just ways that help me understand basic thermodynamics and spontaneity of chemical processes. It's just the way I like to think of things! Please let me know if at any point I pointed out something that was incorrect, or that I have made oversimplifications!
Thank you, just what I was looking for, especially about coupling the reaction
Change in free energy can occur in two ways of a molecules. either free energy is released/ consumed in the bond(enthalpy) during rexn or energy is used as vibrating molecules here and there(entropy).
How can we benefit from the energy we get by ATP Hydrolysis? By phosphorylation or by using the released energy (i think it is called gibbs energy) or both ways?
I have a question: in a mitochondrian, if the matrix ATP concentration is high, and the intermembrane space proton concentration is too low to generate sufficient proton-motive force, then
A) ATP synthase will hydrolyze ATP and pump protons into the matrix
B) ATP synthase will increase the rate of ATP synthesis
C) ATP synthase will hydrolyze ATP and pump protons into the intermembrane space
D) ATP synthase will stop working
I’m sorry your question never got answered 5 years later
May be a bit late, but I suggest it would be C), because the ATP-Synthase can also work in reverse. If there is not enough Protons in the intermembrane space, there is no driving force of Protons to fuel ATP-Synthase to generate ATP. And if the ATP concentration of ATP in the matrix vs the intermembrane space is low (i.e. less ATP outside the matrix than inside), ATP-synthase would 'push out' ATP by hydrolizing it and therefore also increasing the proton concentration i the intermembrane space.
What I always find confusing are:
1.) If energy is REQUIRED in some reactions, shouldn't ATP be written on the reactant side since we could be reading it as, for example the hydrolysis reaction, NEEDING ATP and H20 to make ADP and a free phosphate group?
2.) If a reaction is endergonic, meaning the reaction is non-spontaneous, shouldn't ATP be in somewhere in the equation to drive the reaction forward?
ATP isn't the energy. The breaking up of ATP gives energy. But you're right. Calling ATP an energy-currency is very confusing. Bad explanation!!!
thanks!
Helpful... Thanks
thank you very match
thank you!
you said add but its minus... i thought it sum of ( n moles times delta g of products) - sum of (n moles times delta g of reactants) equals delta g of reaction
Gibbs free energy is really confusing :S I understand the idea of spontanaeity and feasibility and the magnitude of the result. I believe that Gibbs free energy is total energy in a system that can be used to do work but... how does chemical reaction produce more energy than dH - which is the heat??
LIke when you use a calorimeter to find dH - the energy released by reaction does work to heat to surroudnings and we can use heat capacity etc to measure that, and this heat can be utilised. So how does gibbs free energy apply to a chemical reaction and hydrolysis of ATP?
I am just confused about what this energy. other than dH really is... and when do we use it/observe it.
I think I must be totally missing the point but could someone shed some light on this topic
:S
The change in Gibbs free energy for a particular chemical transformation from reactants to products is defined as: dG = dH - TdS where T is in Kelvins. I think this thermodynamic state function (independent of path) gives information about the overall spontaneity of the reaction by considering ONLY the properties of the system (a reaction mixture for example) rather than both the system and the surroundings. Equivalently, dG = -TdS(total or universe) = -T(dSsystem + dS(surroundings). But it is often difficult to assess spontaneity by considering both the system and the surroundings. This is why dG it is so useful. If you think about it, the term dH (also q, the heat of a reaction released or absorbed at constant pressure) tells you how much heat is absorbed or released from the system and because dS = dq/T (infinitesimal change in q changes S as dq/T), energy transfers through heat (utilization of or promoting the random motion of atoms) are directly linked to changes in entropy which is, by definition, a measure of total disorder (or the measure of how many ways a system can be described while keeping the total energy constant). Note that heat is not a property of a system, rather, it is simply a WAY of transferring energy. For example, if the reaction is exothermic and released heat (dH < 0), heat flows INTO the surroundings and thus increases the entropy in the surroundings. Likewise, an endothermic reaction absorbs heat from the surroundings and DECREASES the entropy of the surroundings.
Consider the second law of thermodynamics: everything tends to disorder, or, equivalently, the change in entropy of the universe is ALWAYS positive in a spontaneous process. So, it would be expected that dS(total) = dS(system) + dS(surroundings) > 0. Think about a bag of marbles: if you dump the whole thing, what happens? Your marbles roll around everywhere, it creates more disorder, it has the natural TENDENCY to occur. This is just the definition of a spontaneous process! What happens if you take an ice cube out of your freezer and put it on a table at room temperature? It melts right? It has a spontaneous tendency to do so. Entropy covers the dispersal of both energy AND matter.
Now, back to our consideration of the Gibbs free energy. I mentioned above that it is convenient in that it allows us to assess whether or not a process is spontaneous only by considering the state functions of the system alone. Why is this? Well, as I said, a spontaneous change is one where theTOTAL entropy is increased.I also said that heat (NOT work) is a way of transferring energy that results in entropy changes. Finally, because deltaH = q at constant pressure, we can derive the following:
We know that dS(surroundings) = - dq(system) / T (If the system absorbs heat, dqsys > 0 and dS < 0 and vice-versa)
But we can also say that: dS (surroundings) = - dH(system) / T right?
Now we're getting somewhere because we've ALREADY defined the entropy of the surroundings in terms of the change in enthalpy of the system.
The total entropy equation becomes:
dS (total) = dS (system) - (dH(system)/T)
Multiply BOTH sides by -T,
-TdS(total) = dH - TdS
Look familiar? It should! Because, dG = dH - TdS, and -TdS (total)
Why is this significant?
My rambling above should be useful in that delta G depends not on the energy of a system but of the impact a heat transfer has on the surroundings!
So, in considering ATP hydrolysis, delta G, also considered to be the maximum non-expansion work that can be done, is negative and thus can be used to drive endergonic chemical processes such as active transport in and out of cells, muscle contraction, and many more non-spontaneous metabolic reactions. By adding a highly negative delta G to a positive one with a smaller magnitude, the OVERALL free energy change can be negative and thus, be spontaneous. I think that's why we usually refer to ATP as "energy currency" because it supplies the energy required to drive certain biological reactions.
Everything I stated above are just ways that help me understand basic thermodynamics and spontaneity of chemical processes. It's just the way I like to think of things! Please let me know if at any point I pointed out something that was incorrect, or that I have made oversimplifications!
The audio splices are very distracting. Perhaps next time it would be better to just redo the video...
I didn't notice them at all.
Valley Girl 😁
your freaking words are in the fing way of me seeing what your writing
Abuse for the sake of it. Turn the sound off if that's all the problem is. ya big jerk.