Myocyte cytoplasm contains a big number of dissolved metabolites of glucose oxidation. Name one of them that turns directly into lactate:

Answer options

1. Glucose 6-phosphate
2. Fructose 6-phosphate
3. Glycerophosphate
4. Pyruvate
5. Oxaloacetate

Explanation

When sufficient oxygen is not present in the muscle cells for further oxidation of pyruvate and NADH produced in glycolysis, NAD+ is regenerated from NADH by reduction of pyruvate to lactate. Pyruvate is converted to lactate by the enzyme lactate dehydrogenase.