Tricarboxylic Acid Cycle

TCA cycle

The ______ starts with the condensation of acetyl group with oxaloacetic acid (OAA) and water to yield citric acid.

Citrate synthase

The reaction is catalysed by the enzyme ______ and a molecule of CoA is released.

Isocitrate

Citrate is then isomerised to ______.

Decarboxylation

It is followed by two successive steps of ______, leading to the formation of α-ketoglutaric acid and then succinyl-CoA.

Succinyl-CoA

In the remaining steps of citric acid cycle, ______ is oxidised to OAA allowing the cycle to continue.

GTP

During the conversion of succinyl-CoA to succinic acid a molecule of ______ is synthesised.

Coupled reaction

In a ______, GTP is converted to GDP with the simultaneous synthesis of ATP from ADP.

NAD+

There are three points in the cycle where ______ is reduced to NADH + H+.

FAD+

There is one point where ______ is reduced to FADH2.

Acetyl CoA

The continued oxidation of ______ via the TCA cycle requires the continued replenishment of oxaloacetic acid, the first member of the cycle.

NADH and FADH2

The regeneration of NAD+ and FAD+ from ______ respectively is required for the continued oxidation of acetyl CoA via the TCA cycle.

respiration

The summary equation for this phase of ______ may be written as follows.

glucose

We have till now seen that ______ has been broken down to release CO2 and eight molecules of NADH + H+.

NADH + H+

Two of FADH2 have been synthesized besides just two molecules of ATP in TCA cycle. You may be wondering what the role of the ______ and FADH2 that is synthesized.

ATP

Neither O2 has come into the picture nor the promised large number of ______ has yet been synthesized.

O2

Let us now understand the role of ______ in respiration and how ATP is synthesized.