Final answer:
Leucine and lysine cannot contribute to gluconeogenesis, and all other amino acids can contribute to ATP production, protein synthesis, and energy production.
Step-by-step explanation:
Leucine and lysine are the two amino acids that cannot contribute to gluconeogenesis, which is the process of generating glucose from non-carbohydrate sources. Gluconeogenesis is an important metabolic pathway that occurs mainly in the liver and kidneys, and it involves the conversion of amino acids, lactate, and glycerol into glucose.
The other amino acids, except leucine and lysine, can contribute to ATP production through various metabolic pathways. Amino acids can be oxidized in the mitochondria to produce ATP through the process of oxidative phosphorylation. Additionally, some amino acids can be converted into intermediates of carbohydrate metabolism, such as pyruvate or oxaloacetate, which can be used for energy production through the Krebs cycle.
Furthermore, amino acids are the building blocks of proteins, and they are involved in the process of protein synthesis. During protein synthesis, amino acids are linked together by peptide bonds to form polypeptides and ultimately proteins.