Which reaction transforms acetyl-CoA and oxaloacetate into citrate?

The transformation of acetyl-CoA and oxaloacetate into citrate takes place via a condensation reaction. This type of reaction involves the combining of two molecules to form a larger one, with the concurrent loss of a small molecule, often water. In this case, acetyl-CoA and oxaloacetate undergo a condensation reaction to produce citrate and coenzyme A as a byproduct.

This step is crucial in the citric acid cycle because it initiates the series of reactions that will ultimately lead to energy production through the oxidation of the acetyl group that comes from acetyl-CoA. The merging of the two substrates results in the formation of a six-carbon compound, citrate, which is essential for continuing through the metabolic pathway. Understanding this transformation is key to grasping the flow of carbon through the cycle and how energy is harvested in cellular respiration.