This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Glycogen, Subject name: Biochemistry
Which of the following substrates can't contribute to net gluconeogenesis in mammalian liver? 
Select and explain. 
A. Alanine, B. Glutamate, C. Palmitate, D. Pyruvate
C: Palmitate
Answer: C: Palmitate 
Explanation: Palmitate can't contribute to net gluconeogenesis in mammalian liver Palmitate Fatty acid with 16 carbon atoms Not a substrate of gluconeogenesis. Even chain fatty acids yield Acetyl CoA upon oxidation. Odd chain fatty acid acts as a substrates of gluconeogenesis Propionyl CoA- the product of their oxidation can enter TCA cycle through formation of succinyl CoA Alanine, pyruvate and glutamate are glucogenic.