6. The co-enzyme S-CoA is used twice during this cycle. Why is this co- enzyme useful, and what is the result of using it in each of those two occasions? 7. The Krebs cycle is a circle. What do you think would happen if you removed one of the compounds from that circle to make an amino acid (this does happen, Alpha-ketogluterate is the basic building block for many amino acids)? The cell has a variety of other pathways that can make oxaloacetate (the final 4 carbon product in the krebs cycle) from

Krebs or citric acid cycle is the main source of energy for cells and an important part of aerobic respiration. The cycle harnesses the available chemical energy of acetyl coenzyme A (acetyl CoA) into the reducing power of nicotinamide adenine dinucleotide (NADH).