Anaerobic metabolism produces a net of 2 molecules of ATP per glucose molecule. This is significantly less than the 36-38 ATP molecules produced through aerobic metabolism.

Here's a breakdown:

* Glycolysis: This is the first stage of both aerobic and anaerobic respiration. In glycolysis, glucose is broken down into two pyruvate molecules, producing a net gain of 2 ATP and 2 NADH.

* Fermentation: In anaerobic conditions, pyruvate is converted into lactate or ethanol (depending on the organism) to regenerate NAD+ for glycolysis to continue. This process doesn't directly produce any ATP.

Therefore, the total ATP produced in anaerobic metabolism comes solely from glycolysis, resulting in 2 ATP molecules per glucose molecule.