Quick Bio/chem question

[puncho]

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Which of the following metabolic processes is endergonic?

1) C6H12O6 + 6O2 -> 6CO2 + 6H2O
2) 6CO2 + 6H2O -> C6H12O6 + 6O2
3) ATP + H2O -> ADP + Pi
4) Electron flow along the electron transport chain
5) None of the above

Endergonic means it requires energy...so since bond breaking also requires energy, wouldn't 1 and 3 be correct??

 

[dat_student]

Which of the following metabolic processes is endergonic?

1) C6H12O6 + 6O2 -> 6CO2 + 6H2O
2) 6CO2 + 6H2O -> C6H12O6 + 6O2
3) ATP + H2O -> ADP + Pi
4) Electron flow along the electron transport chain
5) None of the above

Endergonic means it requires energy...so since bond breaking also requires energy, wouldn't 1 and 3 be correct??

I'd say 1 is the best answer.

 

[mochafreak]

I chose #2 on test and I believe that is correct. I thought of the question in terms of catabolism and anabolism. Your body breaks down ATP, etc. which is catabolic process to produce energy (exergonic). Anabolism is the formation of larger molecules, which requires energy (ATP) (endergonic). You are right about the bond breaking requiring energy, but think that ATP to ADP is major exergonic process of body...

 

[sailinx]

Which of the following metabolic processes is endergonic?

1) C6H12O6 + 6O2 -> 6CO2 + 6H2O
2) 6CO2 + 6H2O -> C6H12O6 + 6O2
3) ATP + H2O -> ADP + Pi
4) Electron flow along the electron transport chain
5) None of the above

Endergonic means it requires energy...so since bond breaking also requires energy, wouldn't 1 and 3 be correct??

2 should be the right answer. Yes bond breaking does require energy but you have to see if the over all process releases or consumes energy. (Think endergonic as endothermic and exergonic as exothermic - easy way to remember).
Only 2 satisfies that condition as photosynthesis is required to make glucose.

 

[dat_student]

I chose #2 on test and I believe that is correct. I thought of the question in terms of catabolism and anabolism. Your body breaks down ATP, etc. which is catabolic process to produce energy (exergonic). Anabolism is the formation of larger molecules, which requires energy (ATP) (endergonic). You are right about the bond breaking requiring energy, but think that ATP to ADP is major exergonic process of body...

which test is this?

 

[puncho]

it's from dat achiever, and yeah #2 is the right answer.

 

[dat_student]

...but you have to see if the over all process releases or consumes energy. (Think endergonic as endothermic and exergonic as exothermic - easy way to remember).
Only 2 satisfies that condition as photosynthesis is required to make glucose.

I think 1, 2 and 4 produce energy (ATP). Overall, in all 3 cases energy output > energy input. At least, in #1, some bonds are broken and in that stage it's endergonic.

 

[Flipper405]

I chose #2 on test and I believe that is correct. I thought of the question in terms of catabolism and anabolism. Your body breaks down ATP, etc. which is catabolic process to produce energy (exergonic). Anabolism is the formation of larger molecules, which requires energy (ATP) (endergonic). You are right about the bond breaking requiring energy, but think that ATP to ADP is major exergonic process of body...

I agree here. I would choose #2. 👍

 

[dat_student]

I agree here. I would choose #2. 👍

ok, ok, ok consensus wins. agreed. overall, it's endergonic

2 is endergonic

This is what confused me:

The exergonic light-dependent reactions of photosynthesis convert light energy into chemical energy, producing ATP and NADPH. These reactions occur in the thylakoids of the chloroplasts. The products of the light-dependent reactions, ATP and NADPH, are both required for the endergonic light-independent reactions.
Ref.:
http://www.cat.cc.md.us/courses/bio141/lecguide/unit2/eustruct/photo.html

 

[dat_student]

I agree here. I would choose #2. 👍

ok, ok, ok consensus wins. agreed. overall, it's endergonic

2 is endergonic

This is what confused me:

The exergonic light-dependent reactions of photosynthesis convert light energy into chemical energy, producing ATP and NADPH...The products of the light-dependent reactions, ATP and NADPH, are both required for the endergonic light-independent reactions.
Ref.:
http://www.cat.cc.md.us/courses/bio141/lecguide/unit2/eustruct/photo.html

 

[dentalengineer]

I agree here. I would choose #2. 👍

I'd choose #2. In Endergonic reactions products have more energy than the reactants.

 

[dinesh]

This is what they actually ask on the DAT which you take AFTER university?:S

It's a no brainer

1) C6H12O6 + 6O2 -> 6CO2 + 6H2O--->> that is respiration, why would you want to USE energy in respiration when the entire point is to RELEASE(i.e. be exergonic) energy.

2) 6CO2 + 6H2O -> C6H12O6 + 6O2----->>> Photosynthesis-->> light trapped in light dependant stage--> Definatly Engergonic

3) ATP + H2O -> ADP + Pi---Water needed for hydrolysis of ATP to RELEASE energy by the breaking of a phosphodiester bond.


4) Electron flow along the electron transport chain--->> there is energy LOSS as the electrons flow, then again this is packaged or rather used to fuel the proton pump


Your answer is therefore 2.

 

[dat_student]

2) 6CO2 + 6H2O -> C6H12O6 + 6O2----->>> Photosynthesis-->> light trapped in light dependant stage--> Definatly Engergonic

The light-dependent portion of photosynthesis is actually exergonic. 😉
The light-independent portion of photosynthesis is endergonic. 😉

Overall, it's endergonic.

4) Electron flow along the electron transport chain--->> there is energy LOSS as the electrons flow, then again this is packaged or rather used to fuel the proton pump

Don't we need to input energy to move electrons from one carrier to next? Wouldn't that make it endergonic? I think they probably included ATP generation in the movement of electrons to make it exergonic. NOT sure about this. Anyhow, given the fact that overall 2 is endergonic we can safely bypass this answer choice.

 

[IcemanDDS]

Umm, 2 is the right answer. All the other choices are obviously wrong except for number 4. In ETC, some energy is used to promote the outflux of H ions but overall energy is produced, so not technically endergonic.

 

[peace2c]

Don't we need to input energy to move electrons from one carrier to next? Wouldn't that make it endergonic? I think they probably included ATP generation in the movement of electrons to make it exergonic. NOT sure about this. Anyhow, given the fact that overall 2 is endergonic we can safely bypass this answer choice.

Electron flow along the ETC is actually part of cellular respiration (1), which is generally exergonic throughout. You're right, energy is required to overcome the activation enerrgy barrier when moving an electron from one carrier to the next. But since the energy released in passing the electron to a more stable carrier is greater than the next energy input required, such cascading processes down the hill will not only be exergonic but be spontaneous all the way till the final electron acceptor, oxygen, terminates these. It's this exergonic flow of electrons that has indirectly led to the endergonic synthesis of ATPs via the protons pumped across the membrane.

(Not sure if I've explained the above well. But, you're welcome to throw in more questions if need be.)

 

[dat_student]

Electron flow along the ETC is actually part of cellular respiration (1), which is generally exergonic throughout. You're right, energy is required to overcome the activation enerrgy barrier when moving an electron from one carrier to the next. But since the energy released in passing the electron to a more stable carrier is greater than the next energy input required, such cascading processes down the hill will not only be exergonic but be spontaneous all the way till the final electron acceptor, oxygen, terminates these. It's this exergonic flow of electrons that has indirectly led to the endergonic synthesis of ATPs via the protons pumped across the membrane.

(Not sure if I've explained the above well. But, you're welcome to throw in more questions if need be.)

Ok, I understood everything but this:

You said synthesis of ATP is endergonic. It makes sense. Anabolism is usually endergonic. Doesn't this make answer choice #3 exergonic since #3 is a breakdown of ATP and release of energy?

P.S. I've learned quite a lot about exergonic, endergonic stuff. Thanks to you and other SDNers. 😉

 

[peace2c]

Ok, I understood everything but this:

You said synthesis of ATP is endergonic. It makes sense. Anabolism is usually endergonic. Doesn't this make answer choice #3 exergonic since #3 is a breakdown of ATP and release of energy?

P.S. I've learned quite a lot about exergonic, endergonic stuff. Thanks to you and other SDNers. 😉

Exactly. Just as you've said so, the reverse of an endergonic reaction is understandably exergonic, making #3 one of the wrong answers. [Note: The question here is looking for an endergonic process.]

 

[dat_student]

Exactly. Just as you've said so, the reverse of an endergonic reaction is understandably exergonic, making #3 one of the wrong answers. [Note: The question here is looking for an endergonic process.]

Thanks. Now, I got it.

 

[BenignDMD]

Thanks. Now, I got it.

endergonic reactions produce new patterns of order, entropy...they tend to increase the order

exergonic, on the other hand, are reactions which yield decreased order

making 2 the right answer