Glycolysis is the process of breaking down glucose into two molecules of pyruvate, while gluconeogenesis is the process of synthesizing glucose from non-carbohydrate precursors. Both processes occur in the liver and play crucial roles in maintaining blood glucose levels.In glycolysis, the net ATP yield is 2 ATP molecules per glucose molecule. The breakdown of glucose involves two phases: the energy investment phase and the energy generation phase. In the energy investment phase, 2 ATP molecules are consumed, while in the energy generation phase, 4 ATP molecules are produced. Therefore, the net ATP yield is 2 ATP molecules 4 produced - 2 consumed .Gluconeogenesis, on the other hand, is an energy-consuming process. It requires the input of 6 ATP molecules 4 ATP and 2 GTP to synthesize one glucose molecule from two molecules of pyruvate. This process is essentially the reverse of glycolysis, with some modifications to bypass the irreversible steps of glycolysis.When comparing the energy efficiency of both processes, glycolysis is an energy-generating process, while gluconeogenesis is an energy-consuming process. Glycolysis is more energy-efficient as it produces ATP, whereas gluconeogenesis requires ATP input to synthesize glucose. However, it is essential to note that both processes serve different purposes in the body. Glycolysis provides energy in the form of ATP, while gluconeogenesis maintains blood glucose levels during fasting or prolonged exercise when glucose supply is low.In summary, glycolysis has a net ATP yield of 2 ATP molecules per glucose molecule, while gluconeogenesis consumes 6 ATP molecules to produce one glucose molecule. Glycolysis is more energy-efficient, but both processes are crucial for maintaining energy homeostasis in the body.