Blood Sugar Regulation- Insulin and Glucagon
Soon after a meal, the digestive system begins to break down the food you have eaten the carbohydrates in this food are broken out into a simple sugar called glucose. As this glucose is absorbed from your digestive system into your bloodstream your blood sugar levels increase.
Your circulatory system then carries the glucose to muscle cells throughout your body where it is used to generate energy. Here's the important part in order to get that glucose that's now in your bloodstream into the muscle cells you need to have insulin present to trigger that uptake event.
Insulin and Glucagon - Chemical Processes
Insulin is a small protein hormone produced by your pancreas. As the concentration of glucose in your bloodstream Rises your pancreas senses this increase and is stimulated to release insulin into the bloodstream. The main purpose of insulin is to lower blood sugar. The newly released insulin plays a key role in regulating the concentration of glucose in your blood a process known as glucose homeostasis.
The insulin that is now released into your bloodstream binds to the extracellular domain of receptor proteins found on the surface of the liver, muscle, and fat cells. This binding triggers the autophosphorylation of the intracellular domains which in turn phosphorylate a specific substrate signalling protein.
This protein then phosphorylates other downhill signalling proteins leading to an amplification of the signal at each step. This overall signalling process is known as a signal transduction cascade. One important consequence of this signal cascade is the movement of glucose transport proteins called gluts, towards the cell surface.
As these storage vesicles fuse with the cell membrane the number of gluts present on the surface of the cells increases allowing the glucose to enter the cell. As a result, the glucose concentration in the bloodstream decreases.
If you consume an entire 32-ounce bottle of soda approximately one litre. Your mid-study snack contained 100 grams of sugar and 400 calories. At first, you might have a burst of energy, but 30 minutes later you begin to feel light-headed and cats seem to keep your eyes open or your mind from wandering.
The cells of your body are fueled by glucose molecules that travel throughout your body in the bloodstream. Because glucose is so important your body responds to fluctuations in blood glucose levels to maintain stable levels through homeostasis.
After consuming food the mouth and stomach begin the process of mechanical and chemical digestion. The partially digested food moves from the stomach to the small intestine where larger molecules are further broken down.
Smaller molecules like monosaccharides glucose and fructose. Are absorbed by the cells lining the intestine glucose passes out of the cells and into the interstitial fluid then into the bloodstream. Once individual glucose molecules move into your bloodstream your blood glucose level rises rapidly.
Trigger Your Fat Burning Hormone - Glucagon
The high sugar content of the soda causes a spike in blood glucose triggering a hyperglycemic condition. The pancreas detects an increase in glucose levels in the bloodstream. In response, the beta cells of the pancreas islets produce and secrete the hormone insulin into the bloodstream.
Insulin binds to cell surface receptors and stimulates the transport of glucose into the cells of the body, because of this rapid increase of insulin in response to a large amount of glucose from the soda too much glucose is removed from the blood and stored as glycogen inside the liver and muscle cells.
As a result, your blood is now glucose deficient a hypoglycemic condition. This low blood glucose level can cause lightheadedness fatigue and hunger. In response to glucose deficient blood, the alpha cells of the pancreatic islets will produce and secrete the hormone glucagon. once glucagon levels rise in the bloodstream.
Glucagon will diffuse out of the blood and bind to cell surface receptors in the liver, triggering the conversion of glycogen to glucose in liver cells. The stored glucose is released back into the bloodstream until homeostasis has been achieved.
The consumption of complex carbohydrates instead of simple sugars like the ones found in the soda results in a lower spike in blood glucose. Complex carbohydrates like those found in healthier snacks take longer to digest so glucose is slower to enter the bloodstream.
Homeostasis of blood glucose levels is more easily maintained because the drastic changes to glucose concentrations are diminished without feelings of hunger or fatigue. The hunger experience during bouts of low blood sugar in addition to disrupting short-term homeostasis can be a contributing factor to overeating and long term problems like obesity. Glucose is also taken up by adipose cells during the spike in blood glucose and can be converted into fat.
This along with exaggerated portion size sedentary lifestyles and poor nutritional choices are contributors to the worldwide obesity epidemic. Consuming more calories from natural sources containing complex carbohydrates your body can maintain homeostasis of blood glucose levels more effectively. This can reduce your risk of gaining weight and improve your overall health.
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