Final answer:
The process of forming glucose from metabolic intermediates like pyruvate and lactate is known as gluconeogenesis. It primarily takes place in the liver, especially during low glucose conditions such as fasting. Glycogenesis is the process of forming glycogen from glucose, which allows for glucose storage.
Step-by-step explanation:
Gluconeogenesis: The Synthesis of Glucose
The process of forming glucose from various metabolic intermediates is called gluconeogenesis. This anabolic pathway allows for the synthesis of glucose from non-carbohydrate sources such as pyruvate, lactate, glycerol, and certain amino acids like alanine or glutamine. It mainly occurs in the liver and to a lesser extent in the kidneys, especially during periods of fasting, starvation, or low carbohydrate intake to maintain normal blood glucose levels.
During glycolysis, glucose undergoes a series of reactions to eventually form pyruvate, yielding energy in the form of ATP. Glycolysis is a catabolic process and is essentially the opposite of gluconeogenesis. Moreover, glucose, after its uptake into the cell, is phosphorylated by the enzyme hexokinase to form glucose-6-phosphate. This prevents the glucose from diffusing back out of the cell and makes it available for subsequent metabolic processes, such as glycolysis or to be stored as glycogen.
Glycogenesis is the process of glycogen synthesis from glucose, where glucose-6-phosphate is converted to glucose-1-phosphate which further participates in the formation of the storage molecule, glycogen. Glucose can thus be stored and utilized during times when the body needs an energy source, providing a balance in the body's metabolic needs.