18. A key intermediate in the catabolism of fatty acids with uneven numbers of carbon atoms is(A)malonyl-CoA(B)propionyl-CoA(C)oxaloacetate(D)phosphoenolpyruvate

6. Which one of the following statements is true about catabolic pathways?(A)They combine molecules into more complex and energy-rich molecules.(B)They belong to the reduction reaction.(C)They are usually coupled with anabolic pathways and generate energy in the form of ATP.(D)They do not need enzyme catalysts.