Answer:
Matrix of mitochondria
Explanation:
Citric acid cycle is also known as the Krebs cycle or tricarboxylic acid cycle. It occurs in the matrix of mitochondria. As in glycolysis, only partial oxidation of glucose takes place, therefore, the final product of glycolysis that is pyruvate is converted into acetyl CoA in the matrix of mitochondria and here it's complete oxidation takes place by citric acid cycle.
Citric acid cycle is important in producing electron donors in the form of NADH and FADH2 which provide electron source during the oxidative phosphorylation process to create ATPs.
Therefore the reaction of the citric acid cycle occurs in the matrix of mitochondria in eukaryotes.
