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How does the structure of alanine contribute to its zwitterion form?
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Alanine contains a NH3 group, an alpha hydrogen, a methyl group, and a carboxyl group, allowing it to exist as a zwitterion with neutral overall charge.
How does the metabolism of amino acids support gluconeogenesis?
Amino acids can be converted into intermediates that enter the gluconeogenesis pathway to produce glucose from non-carbohydrate sources.
Why is the conversion of amino acids into Krebs Cycle intermediates important for energy metabolism?
This conversion allows amino acids to contribute to ATP production and support gluconeogenesis by providing intermediates for energy and glucose generation.
What clinical conditions might high AST and ALT levels in combination with increased creatine kinase and troponin indicate?
These levels may indicate myocardial infarction as they suggest muscle damage including cardiac tissue.
How can elevated levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) indicate liver damage?
Elevated ALT and AST in blood serum can suggest liver cell damage as these enzymes are normally contained within liver cells.
What is the significance of glutamine in the process of gluconeogenesis?
Glutamine deaminates to produce glutamate which can then convert into succinyl-CoA, an intermediate of the Krebs Cycle, contributing to gluconeogenesis.
What potential metabolic pathways can pyruvate take after transamination?
Pyruvate can be converted to lactic acid, used in gluconeogenesis, or transformed into acetyl CoA for oxidation in the Krebs Cycle.
What are the products of the reaction between aspartate and alpha-ketoglutarate?
The reaction produces glutamate and oxaloacetate, facilitated by aspartate aminotransferase.
What role does alanine aminotransferase play in the transamination process?
Alanine aminotransferase catalyzes the transfer of an amine group from alanine to alpha-ketoglutarate, producing pyruvate and glutamate.
Outline the conversion of lactic acid into glucose via the Cori Cycle.
Lactic acid in muscle is transported to the liver, converted to pyruvate by lactate dehydrogenase, then via gluconeogenesis, pyruvate is converted to glucose.
Explain the importance of pyridoxal phosphate in the function of aminotransferase enzymes.
Pyridoxal phosphate, derived from Vitamin B6, is a co-enzyme for aminotransferases and facilitates the transfer of amino groups during transamination.
Explain the fate of pyruvate formed during transamination in muscle tissue.
Pyruvate can be converted to lactic acid or acetyl CoA, with acetyl CoA entering the Krebs Cycle for ATP production.
How does oxidative deamination of glutamate contribute to the energy metabolism in the liver?
By producing alpha-ketoglutarate, which can enter the Krebs Cycle, and generating ammonia for disposal in the urea cycle.
Describe how ammonia produced from glutamate is detoxified in the liver.
Ammonia is converted to ammonium and then enters the mitochondria to be processed through the urea cycle.
What is the role of glutamate dehydrogenase in amino acid metabolism in the liver?
Glutamate dehydrogenase catalyzes oxidative deamination of glutamate, producing alpha-ketoglutarate and ammonia, with NADP+ being reduced to NADPH.
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