What happens to carbon skeletons of amino acids in catabolic pathways?

When amino acids undergo catabolism, their carbon skeletons play a crucial role in energy metabolism. During catabolic pathways, the amino acids are deaminated, meaning the amino group is removed, and what remains is the carbon skeleton. These carbon skeletons can then enter various metabolic pathways.

Specifically, carbon skeletons can be converted into intermediates of the Krebs cycle (citric acid cycle), which is a series of reactions that produce energy through the oxidation of acetyl-CoA derived from carbohydrates, fats, and proteins. This process ultimately leads to the production of ATP, the energy currency of the cell. Additionally, these carbon skeletons can also be transformed into glucose through gluconeogenesis or converted into fatty acids via lipogenesis, depending on the body's energy needs and nutrient availability.

This highlights the versatility of amino acids in energy production and their integration into broader metabolic networks, reinforcing the importance of amino acids not just as building blocks for proteins but also as significant contributors to energy metabolism.