What is a key characteristic of glycolysis regarding oxygen?

Glycolysis is a crucial metabolic pathway that breaks down glucose to produce energy. A key characteristic of glycolysis is its ability to function with or without the presence of oxygen. This means that glycolysis can take place in both aerobic and anaerobic conditions. In the presence of oxygen, the pyruvate produced from glycolysis can enter the mitochondria for further oxidation, while in the absence of oxygen, it can undergo fermentation processes to regenerate NAD+ for glycolysis to continue. This versatility makes glycolysis an essential step in cellular respiration, adaptable to different cellular environments. The other options imply a strict requirement or total consumption of oxygen, which does not reflect the true nature of glycolysis.