The Krebs cycle involves the aerobic breakdown of glucose for energy. In the first reaction of the Krebs Cycle, the enzyme Aconitase converts Citric acid to its isomer, the molecule isocitrate. The Keq’ for this reaction is approximately 0.1. ∆G°' for this reaction is therefore and the reaction is .

The reaction is at equilibrium

Explanation:

The Krebs cycle is an aerobic pathway because the final electron acceptor required is oxygen.

The most common situation leading to a disruption in the function of Krebs cycle is the lack of oxygen to accept electrons in the electron transport chain.  

The conversion of citrate to isocitrate (isomerization), is catalyzed by the enzyme, aconitase (also known as aconitate hydratase). The hydroxyl (alcohol) group of citrate is moved to an adjacent carbon so that it can be oxidized to form a keto group.

This reaction involves generation of an enzyme-­bound intermediate, cis­aconitate. At equilibrium, there exists 90% citrate, 3% cis­aconitate, and 7% isocitrate; hence the equilibrium of aconitase lies toward citrate formation.

Although the aconitase reaction does not require cofactors, it requires ferrous (Fe2+) iron in its catalytic mechanism. This Fe2+ is involved in an iron–sulfur center, which is an essential component in the hydratase activity of aconitase.    

According to Gibb's free energy:

ΔG = 0 - Reaction at equilibrium.

ΔG > 0 - non-spontaneous reaction.

ΔG < 0 - spontaneous reaction.

yes? sounds right, but you didn’t ask a question.

it has to be understood that the sea water contains a huge amount of sodium and chlorine ions and if they enter the cell of the atlantic cod fish, the cell will shrivel and the fish will die. to avoid such a condition, the fish uses active transport for the purpose of removing the ions against the gradient.

explanation:

the atlantic cod is not a maritime osmoconformer. its native application of salts is less than that of the seawater it lives in. it is continually falling water from the gills to the ocean via osmosis.

countering that, the fish is going to be swallowing seawater. but since its internal collection of salts is lower than seawater, the fish will want to go free of excess salt, and since that's going upon a gradient, then active transport, requiring energy, must be used to pump out the salt. much marine fish use the organs to filter out the salt and these fish discharge very straight urine.