Q1 Which of the following can serve as a source of carbon for gluconeogenesis?O cholesterolalanineO acetyl-CoAO palmitic acidall of the above

Gluconeogenesis is the metabolic pathway that produces glucose from non carbohydrate precursors. Essentially it is the reverse of glycolysis but not every step of glycolysis is reversed in gluconeogenesis. Cholesterol is the precursor to steroid hormones like testosterone, progesterone and estrogen. Alanine can undergo deamination to produce pyruvate. Pyruvate is then converted to phosphoenolpyruvate by the action of pyruvate carboxylase and PEP carboxykinase. Phosphoenolpyruvate then enters the gluconeogenesis pathway to produce glucose. Acetyl CoA is starvation state has two possible fates: enter the TCA cycle as citrate and be oxidised into carbon dioxide to generate NADH/FADH2 for ATP synthesis or it can be used for producing ketone bodies like acetoacetate and hydroxybutyrate that serve as fuel for brain cells. Palmitic acid is a fatty acid that is oxidised in the mitochondria via beta oxidation pathway to generate acetyl CoA during prolonged starvation. The correct choice is Alanine.