- Preparatory reaction is so called because it occurs before the citric acid cycle. In this reaction, pyruvate is converted to a 2-carbon acetyl group attached to coenzyme A, or CoA, and CO2 is given off. - It occurs in the matrix of the mitochondria.

Where does the preparatory reaction occur?

The Preparatory Reaction

This reaction occurs in the matrix, or interior, of the mitochondria of cells. Here, the two pyruvate molecules from glycolysis are combined with two coenzyme A (CoA) molecules to produce two acetyl-CoA molecules and two carbon dioxide (CO₂) molecules.

What is formed in the preparatory reaction?

in the preparatory reaction, two pyruvate molecules are converted to acetyl-groups and CO2. the two-carbon acetyl-groups are then carried into the citric acid cycle in the mitochondrial matrix by a molecule called CoA. the innermost compartment of the mitochondrion, filled with a gel-like fluid.