What are the metabolic pathways of glucose after it is absorbed by the small intestine?

The metabolic pathways of glucose after it is absorbed by the small intestine primarily involve its uptake and utilization in various processes to meet the body's energy needs and storage requirements. Once glucose enters the bloodstream, it can be transported to tissues where it undergoes several metabolic fates.

Glycogenesis is the process by which excess glucose is converted into glycogen for storage, primarily in the liver and muscles. This pathway is crucial for maintaining blood glucose levels during fasting and for providing energy during periods of high demand, such as exercise.

Glycolysis is the first step in the breakdown of glucose, where it is converted into pyruvate, generating ATP in the process. This pathway is an essential means of energy production, especially in cells that require rapid energy.

The tricarboxylic acid (TCA) cycle, also known as the Krebs cycle or citric acid cycle, occurs in the mitochondria and further oxidizes the pyruvate derived from glycolysis. This cycle plays a key role in energy production, as it generates NADH and FADH2, which are later used in oxidative phosphorylation to produce additional ATP.

Combining these pathways—glycogenesis for storage, glycolysis for immediate energy production, and the TCA cycle