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.

d concave shape of wave rock

explanation:

the concave shape of wave rock is a very good evidence that supports the evolution of earth due to chemical weathering. if we talk about structure of   wave rock, studies have estimated that it is around 2.7 billion years old. it also serves as the foundation of evidence that it was the place where australian continent began to form.

how the structure of wave rock was created?

studies suggest that structure of wave rock was created when the surrounded area was started to weather due to which deposition of material started on the part of land which now contains wave rock.

the structure of wave rock is considered to be one of the best-known landforms in australia. at the height of around 15 cm, there can be found flared slopes which formulate the margins of hyden rock. it is now assumed by geologists that wave rock was created by subsurface water-induced weathering and not by glaciers, waves or wind.

due to deposition of material over the period of long time, the wave rock became tougher and tougher due to weathering from surrounding terrain. this makes it a physical evidence that supports   the evolution of earth due to chemical weathering.

hope it !

the dark variety, as they are not visible on the dark tree barks

explanation: