This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Biochemistry
Final common pathway of metabolism of carbohydrates, lipids and protein metabolism is ? 
Select and explain. 
A. TCA cycle, B. Glycogenesis, C. Gluconeogenesis, D. None of the above
A: TCA cycle
Answer: A: TCA cycle 
Explanation: Ans. is 'a' i.e., TCA cycle Tricarboxylic acid (TCA) cycle is a series of reactions through which final oxidation of acetyl CoA to CO, and H20 occurs along with generation of ATP.TCA cycle is the final common pathway of the oxidation of the acetyl CoA, formed from carbohydrates, fatty acids and amino acids.It provides electrons which are transferred to ETC where they help in the formation of ATP.