Discuss the interrelationships between anabolic and catabolic pathways. Provide specific examples in your answer.

Question

What will be an ideal response?

Answer 1

Catabolic pathways generate the energy required for anabolic reactions. Catabolic pathways produce intermediates for other pathways, and some intermediates and products of anabolic pathways provide intermediates for catabolic pathways. The Citric acid cycle produces energy to drive amino acid synthesis, and several Citric acid cycle intermediates are substrates for amino acid biosynthesis. For example, oxaloacetic acid is a precursor for half a dozen amino acids, and ?-ketoglutaric acid is a precursor for about four additional amino acids. The pentose phosphate pathway produces the five-carbon sugar required for nucleotide synthesis, and various amino acids are metabolized to produce the nitrogenous bases in nucleotides. The Citric acid cycle produces intermediates and substrates for lipid biosynthesis. Catabolism of amino acids produces a variety of molecules that are intermediates of glycolysis and the Citric acid cycle, and the same is true of lipid catabolism.