Final answer:
A direct result of anaerobic metabolism during hypoxic cell injury is the production of lactate. Anaerobic glycolysis leads to the conversion of pyruvate to lactate, facilitated by lactate dehydrogenase, with a small net yield of ATP.
Step-by-step explanation:
Anaerobic Metabolism and Hypoxic Cell Injury
Under anaerobic conditions, when oxygen supply to cells is limited, cells are forced to rely on anaerobic glycolysis for ATP production. Unlike aerobic respiration, anaerobic glycolysis only produces a small amount of ATP, specifically a net yield of two ATP molecules for each glucose molecule consumed. During this process, lactic acid is produced as a result of the conversion of pyruvate when oxygen is absent or limited.
The enzyme lactate dehydrogenase (LDH) catalyzes this conversion of pyruvate to lactate, and the regeneration of NAD+ is essential for continuing glycolysis in the absence of oxygen. The production of lactic acid is a significant outcome of anaerobic metabolism, and while lactate itself is not necessarily detrimental to muscle function at moderate levels, its accumulation at very high levels can contribute to muscular fatigue.
Therefore, in response to the student's question, a direct result of anaerobic metabolism during hypoxic cell injury is 2) the production of lactate. Other options like increased ATP, tissue ischemia, and the production of free radicals do not directly result from anaerobic metabolism but are related to other aspects or consequences of hypoxic injury.