Glycolysis occurs in the cytosol of cells and is the first step in the breakdown of glucose to extract energy for cellular metabolism. Glycolysis does not require oxygen and can occur in aerobic and anaerobic organisms. So, if anybody asks you, “Is Glycolysis aerobic or anaerobic?!” you should answer that the Glycolysis pathway occurs in both aerobic and anaerobic conditions.
Glycolysis is a metabolic pathway that breaks down glucose into pyruvate. The pyruvate molecules can enter different pathways depending on the presence of oxygen. In aerobic respiration, pyruvate is oxidized in the Krebs cycle and the electron transport chain to produce more ATP. In anaerobic respiration, pyruvate is fermented to produce either lactic acid or ethanol, depending on the organism.
Difference between aerobic and anaerobic Glycolysis
Aerobic Glycolysis
In the presence of oxygen, pyruvate is oxidized to acetyl-CoA by the pyruvate dehydrogenase complex in the mitochondria. Acetyl-CoA enters the citric acid cycle. Heart and brain cells primarily rely on aerobic Glycolysis for energy production. Heart tissue cells cannot tolerate ischemic conditions and usually die in hypoxic conditions.
Anaerobic Glycolysis
In the absence of oxygen in some body cells, such as white muscle fibers, liver, kidney, and heart, pyruvate is converted to lactate in the cytosol by lactate dehydrogenase (LDH) using NADH. Red blood cells use anaerobic Glycolysis to produce energy in aerobic and anaerobic conditions. In anaerobic conditions, bacteria convert pyruvate to ethanol. Initially, pyruvate is converted to acetaldehyde by pyruvate decarboxylase. This enzyme requires TPP and magnesium ions for its function. Acetaldehyde is converted to ethanol by alcohol dehydrogenase. This enzyme contains an iron atom in its structure.
