WANI Dictionary

Gluconeogenesis

Gluconeogenesis is the synthesis of glucose from noncarbohydrate sources. Several important features of gluconeogenesis include:

• Gluconeogenesis typically takes place in the liver and kidney under starvation.
• The noncarbohydrate source includes lactate, glucogenic amino acids, glycerol, and propionate.
• Gluconeogenesis shares many pathways with glycolysis. Three steps of glycolysis, catalyzed by hexokinase (HK), phosphofructokinase (PFK) and pyruvate kinase (PK), are bypassed.

Definitions in the literature

• The synthesis of glucose from noncarbohydrate sources, such as fat and protein. This occurs when the glycogen supplies in the liver are exhausted [1].
• Glucose is produced by the process of gluconeogenesis, the production of glucose from noncarbohydrate starting materials [3].

Harper’s Biochemistry [2] has two conflicting descriptions about gluconeogenesis.

• Gluconeogenesis is the process of synthesizing glucose from noncarbohydrate precursors. The major substrates are the glucogenic amino acids (see Chapter 29), lactate, glycerol, and propionate.