Question

Acetyl-CoA is sometimes formed as a result of protein katabolism. Certain cells (in the muscle for instance) can't use Acetyl-CoA to synthesize fatty acid. If there is no immediate need for energy, can the Acetyl-CoA then be exported out of the cell, so that it may be used for fatty acid synthesis in other tissues?

If so, how is this accomplished? I know Acetyl-CoA can be transported out of the mitochondria using the citrate shuttle, but how would it pass the cell membrane and get transported in the blood?

Answer 1

Acetyl-CoA can be exported out of cells and used for fatty acid synthesis in other tissues. The citrate shuttle facilitates the transportation of acetyl-CoA out of the cell. Acetyl-CoA can be transported in the blood bound to carrier molecules.

Step-by-step explanation:

In certain cells, such as muscle cells, acetyl-CoA cannot be used for fatty acid synthesis. However, it can be exported out of the cell and used for fatty acid synthesis in other tissues.

The transportation of acetyl-CoA out of the cell is facilitated by the citrate shuttle. Acetyl-CoA combines with oxaloacetate to form citrate, which can cross the mitochondrial membrane and enter the cytoplasm. In the cytoplasm, citrate is converted back into acetyl-CoA and oxaloacetate. The acetyl-CoA can then be used for fatty acid synthesis.

Once acetyl-CoA is synthesized in other tissues, it can be transported in the blood bound to carrier molecules, such as albumin, for utilization by other cells.