Question

What happens to the following components to regulate glucose homeostasis after you’ve eaten a milkshake and three cookies

Glucose:

Glycogen:

Extra Glucose:

Extra Amino Acids:

Triglycerides:

Answer 1

Answer:

Glucose Homeostasis is the process by which insulin and glucagon maintain blood sugar within a tight normal range. By increasing glucose uptake by muscles and other organs, insulin helps in reducing the blood glucose level by promoting glycolysis and glucogenesis. Whereas a fall in blood glucose increases the release of glucagon from the pancreas to promote glucose production.

Everything that happens to glucose, amino acids and fat in the well fed state depends upon a high insulin to glucagon ratio.

After a meal of three cookies and milkshake the body comes to phase I of glucose homeostasis, i.e. well fed state. In this state following things happen simultaneously or in close succession:

1. Glucose and fats are oxidized to CO₂ and H₂O in the peripheral tissues, which drive synthetic reactions and maintain cell function.

2. After the meal, increased plasma glucose promotes the release of insulin.

3. Glucose is circulated to all tissues and taken up with help of insulin. Brain is dependent upon glucose catabolism to generate energy (ATP) for its functions. It has to be noted that almost 50% of glucose or even more is utilised by brain alone. In the liver, glucose can be converted into glycogen or pyruvate or even pentoses for generation of NADPH for cellular processes.

4. The liver allows most of the amino acids into circulation so that essential amino acids are available to all cells for their synthetic processes (protein synthesis). However, extra amino acids no more needed for protein synthesis are converted to either glucose or fat. The amino nitrogen from these is converted to urea for excretion.

5. In the final phase when ingested food has been absorbed and appropriately consumed, blood glucose level is maintained by liver by process of glycogenolysis (about 75%) and gluconeogenesis (about 25%).

Glycogenolysis is break up of stored glycogen back to glucose.

Gluconeogenesis generates glucose from non carbohydrate sources like amino acids and fatty acids.

Thus we can see what happens to each component:

Glucose: is circulated in the whole body and utilized by cells for synthetic reactions and other cell functions with the help of hormone insulin.

Glycogen: level is maintained as there is enough glucose in the blood.

Extra Glucose: is processed into pyruvate or converted to either glycogen for storage or used to make pentoses for generation of NADPH for cellular processes.

Extra Amino Acids: The amino acids no more required for protein synthesis are converted either to glucose or to fats. The nitrogen from these amino acids is converted to urea for excretion.

Triglycerides: are converted to fats for storage as there is enough glucose to provide energy and there is not need of metabolising triglycerides or fats for energy.