Final answer:
Yes, glycolysis does require an initial investment of energy, which is provided by two ATP molecules used during the priming step of the process. The energy input is key to splitting glucose into two molecules of pyruvate, leading to a net gain of ATP by the end of glycolysis.
Step-by-step explanation:
Glycolysis Require an Input of Energy:
Glycolysis is a central metabolic pathway that occurs in the cytoplasm of cells, functioning to convert glucose into pyruvate. This process can be divided into two main phases: the energy-consuming phase and the energy-yielding phase. In the first phase, known as the "priming step", two ATP molecules are required to activate glucose and prepare it for the subsequent sequence of enzymatic reactions.
Then, a second ATP molecule is used to convert fructose-6-phosphate into fructose-1,6-bisphosphate, further investing energy into the system. Eventually, these investments are offset by the generation of four ATP molecules, resulting in a net gain of two ATP molecules for the cell. Additionally, high-energy electrons are captured by NAD+ to form NADH, which is later used in the electron transport chain to produce more ATP during cellular respiration.