Final answer:
Acetyl-CoA is the compound that links glycolysis, the TCA cycle, and fatty acid synthesis, playing a crucial role in both energy production and the synthesis of fatty acids.
Step-by-step explanation:
The compound that links glycolysis, the TCA (tricarboxylic acid) cycle, and fatty acid synthesis is Acetyl-CoA. This molecule is a key metabolic intermediate that plays a crucial role in cellular respiration and anabolic pathways. In the process of glycolysis, glucose is broken down into pyruvate, which is then converted into Acetyl-CoA in a reaction known as the oxidative decarboxylation or link reaction. The generated Acetyl-CoA then enters the citric acid cycle, also known as the Krebs cycle, providing energy in the form of ATP, NADH, and FADHâ‚‚. The same Acetyl-CoA is critical for the initiation of fatty acid synthesis, where it is carboxylated to form malonyl-CoA by the enzyme acetyl-CoA carboxylase, the regulation point of fatty acid synthesis.