Can pyruvate be converted back to glucose?

Yes, pyruvate can be converted into glucose through a process known as gluconeogenesis. The first step is the conversion of pyruvate to phosphoenolpyruvic acid (PEP). Pyruvate carboxylase, malate dehydrogenase, and PEP carboxykinase are the 3 enzymes involved in this conversion. Pyruvate carboxylase is located on the mitochondria and converts pyruvate into oxaloacetate. Oxaloacetate is not able to pass through the mitochondrial membranes, and thus it first must be converted into malate by malate dehydrogenase. Malate, which is able to cross the mitochondrial membrane into the cytoplasm, is then converted back into oxaloacetate with another malate dehydrogenase. Oxaloacetate is then converted into PEP via PEP carboxykinase. In step 2 of gluconeogenesis, the conversion of fructose 1,6-bp to fructose-6-P with the enzyme fructose-1-6 phosphatase occurs. In step 3, glucose-6-P is converted to glucose with the enzyme glucose-6-phosphatase. This enzyme is found in the ER.