Which two major catabolic pathways supply carbon skeletons f

Which two major catabolic pathways supply carbon skeletons for sugar and amino acid biosyntheses?

Solution

All amino acids are derived from intermediates of Glycolysis, kreb cycle and pentose phosphate pathway out of this glycolysis and krebs cycle are major pathway e.g The glucose-6-Phosphate giving corbon skleton to histidine, pyruvate giving to Alanine,valine leusine and isoleusine,alpha ketoglutarate giving to glutamate proline and glutamine.

Glycolysis and kreb cycle giving corbon skeleton to sugar majorly glycolysis e.g like pyruvate and citric cycle intermediates.