gluconeogenesis

Examples of gluconeogenesis in the following topics:

• Insulin Secretion and Regulation of Glucagon

  • Glucagon is produced by alpha cells in the pancreas and elevates the concentration of glucose in the blood by promoting gluconeogenesis and glycogenolysis.
  • As these stores become depleted, glucagon then encourages the liver and kidney to synthesize additional glucose by gluconeogenesis.
  • Glucagon also turns off glycolysis in the liver, causing glycolytic intermediates to be shuttled to gluconeogenesis and can induce lipolysis producing glucose from fat.
  • Insulin also inhibits gluconeogenesis and promotes the storage of glucose in fat through lipid synthesis and also by inhibiting lipolysis.

• Pyruvic Acid and Metabolism

  • Pyruvic acid can be made from glucose through glycolysis, converted back to carbohydrates (such as glucose) via gluconeogenesis, or to fatty acids through acetyl-CoA.
  • Pyruvate is also converted to oxaloacetate by an anaplerotic reaction, which replenishes Krebs cycle intermediates; also, oxaloacetate is used for gluconeogenesis.
  • Pyruvate can be converted into carbohydrates via gluconeogenesis, to fatty acids or energy through acetyl-CoA, to the amino acid alanine, and to ethanol.
  • Pyruvic acid can be made from glucose through glycolysis, converted back to carbohydrates (such as glucose) via gluconeogenesis, or to fatty acids through acetyl-CoA.

• Biosynthesis and Energy

  • The process of gluconeogenesis, characterized by the production of glucose or fructose from noncarbohydrate precursors, is an ubiquitous process.

• Polysaccharide Biosynthesis

  • Gluconeogenesis (abbreviated GNG) is a metabolic pathway that results in the generation of glucose from non-carbohydrate carbon substrates such as phosphoenolpyruvate (PEP).
  • This reaction is a rate-limiting step in gluconeogenesis.

• Metabolic Changes

  • Increased liver metabolism is also seen, with increased gluconeogenesis leading to increased maternal glucose levels.

• Carbohydrates: Sources, Uses in the Body, and Dietary Requirements

  • Humans can synthesize some glucose (in a set of processes known as "gluconeogenesis") from specific amino acids or from the glycerol backbone in triglycerides and, in some cases, from fatty acids.

• Fermentation Without Substrate-Level Phosphorylation

  • Pyruvic acid can be made from glucose through glycolysis, converted back to carbohydrates (such as glucose) via gluconeogenesis, or to fatty acids through acetyl-CoA.

• Substrates for Biosynthesis

  • Additional pathways that require substrates or metabolites produced by the glycolytic pathway include: gluconeogenesis, lipid metabolism, the pentose phosphate pathway, and the TCA.

• Adrenal Glands

  • The glucocorticoids stimulate the synthesis of glucose and gluconeogenesis (converting a non-carbohydrate to glucose) by liver cells.
  • It also stimulates the production of glucose from fats and proteins, which is a process referred to as gluconeogenesis.

• Adrenergic Neurons and Receptors

  • Further effects include glycogenolysis and gluconeogenesis from adipose tissue and liver, as well as secretion from sweat glands and Na+ reabsorption from kidney.