Welcome Guest Search | Active Topics |

Tag as favorite
Glycolysis
Options
Previous Topic Next Topic
Vaishaalie_6729
#1 Posted : Thursday, July 08, 2021 4:57:13 AM
Rank: Newbie

Groups: Registered
Joined: 5/17/2021
Posts: 6

Thanks: 0 times
Was thanked: 0 time(s) in 0 post(s)
Hello I have a question on glycolysis!

It is to my understanding than steps 1, 3 and 10 in glycolysis are irreversible, because they are exergonic processes. It is also to my understanding that catabolic reactions are exergonic. Catabolic reactions occur when you break one large molecule into two smaller ones, however, in step 3, we are adding a phosphate group (fructose-6-phosphate to fructose-1-6-biphosphate) - wouldn't this reaction be anabolic (as we are adding two molecules (fructose-6-phosphate + Pi) together to create a larger molecule). OR would it be catabolic (-ve free energy) because ATP is broken down into ADP + Pi. If this is the case, then shouldn't step 10 be anabolic (+ve free energy) as ATP is being made? I would love any clarification on this topic.
Back to top
Report? | Edit by user
INSTR_Molly_129
#2 Posted : Saturday, July 10, 2021 5:12:05 PM
Rank: Advanced Member

Groups: Registered
Joined: 5/23/2021
Posts: 74

Thanks: 0 times
Was thanked: 0 time(s) in 0 post(s)
Hi Vaishaalie,

All steps in glycolysis requiring a kinase of some sort is an irreversible step. In general, catabolic reactions result in an exergonic reaction, but during the kinase step, there are two molecules at play. One is undergoing an anabolic reaction and the other is catabolic.

The breaking down of a phosphate group from ATP to ADP makes it catabolic, and results in a release of energy (exergonic).

The build up of the molecule from F6P to F1,6P is anabolic and results in absorption of energy (endergonic).

The difference in Gibbs free energy is the summation of the energy that is gained and lost. Overall, the entire reaction as a whole is an endergonic reaction.

Hope that clarifies this!

Cheers,

Molly
Back to top
Report?
Users browsing this topic
Guest (2)
Tag as favorite
You cannot post new topics in this forum.
You cannot reply to topics in this forum.
You cannot delete your posts in this forum.
You cannot edit your posts in this forum.
You cannot create polls in this forum.
You cannot vote in polls in this forum.

Clean Slate theme by Jaben Cargman (Tiny Gecko)
Powered by YAF | YAF © 2003-2009, Yet Another Forum.NET
This page was generated in 0.075 seconds.