Optometry Admission Test (OAT) Practice

What is gluconeogenesis in the liver during homeostasis?

1. The breakdown of glycogen

2. The formation of glucose from non-glucose precursors

3. The production of amino acids

4. The synthesis of fatty acids

The correct answer is: The formation of glucose from non-glucose precursors

Gluconeogenesis is the metabolic pathway that results in the generation of glucose from non-carbohydrate substrates. This process is particularly important during periods of fasting, starvation, or intense exercise when blood glucose levels need to be maintained to supply energy to vital organs, especially the brain. In the liver, gluconeogenesis primarily utilizes precursors such as lactate, glycerol, and certain amino acids to synthesize glucose. This pathway serves to replenish glucose stores and maintain homeostasis, ensuring that the body has a continuous supply of glucose for energy needs when glycogen stores are depleted. The other options are not correct in this context. The breakdown of glycogen refers to glycogenolysis, which is the release of glucose from glycogen stores. The production of amino acids is a separate metabolic process, often involving transamination and other reactions related to protein metabolism. The synthesis of fatty acids, or lipogenesis, involves converting excess carbohydrates or proteins into fatty acids for storage and is also distinct from gluconeogenesis.