Which of the following activities does NOT lead to cellular energy production?

Cellular respiration, glycolysis, and oxidative phosphorylation are all processes that produce ATP, which is the energy currency of the cell.
Gluconeogenesis is the process of synthesizing glucose from non-carbohydrate precursors, such as lactate, pyruvate, and amino acids. It is an energy-consuming process, as it requires the hydrolysis of ATP.
Therefore, the answer is gluconeogenesis.