What molecule is responsible for carrying the acetyl group from pyruvate into the citric acid cycle?

During Glycolysis, one molecule of glucose is converted into two molecules of pyruvic acid in the cytoplasm of the cell. Pyruvic acid is then moved into the inner matrix of the mitochondria, which is the organelle within the cell responsible for the generation of energy. The pyruvic acid molecule is converted into acetyl Co-A, which is the molecule that enters the Krebs Cycle. In the Krebs Cycle, acetyl Co-A is attached to oxaloacetate acid to form citric acid; the Krebs Cycle is alternately known as the citric acid cycle.