Gluconeogenesis Simply Explained

Gluconeogenesis - literally: sugar rebuilding - is a clever trick our body uses to keep blood sugar levels stable. Our brain needs sugar all the time. The liver does have some stores in the form of glycogen, but not much, and it's reluctant to release that store. Muscles also have glycogen, but they don't give it away easily.

 So as soon as you haven't eaten for a few hours and your blood sugar levels start to drop, the liver starts making its own sugars for the brain. She gets the signal to do this from the pancreas: the sugar-scavenging hormone insulin disappears from the blood, and glucagon appears in its place. This hormone tells the liver,We need sugar!

Gluconeogenesis: The Ingredients

Our liver can only produce sugar from very specific substances. It obtains the ingredients from the muscle metabolism. On the one hand, there is lactic acid, which is produced when muscles work anaerobically without oxygen. Another possible raw material is glycerin, the small connecting piece in fat molecules.

 However, the most important starting material for gluconeogenesis, because it is the most readily available, is protein, or to be more precise, its building blocks, the amino acids. There are 22 different amino acids in the human body, 16 of which are used to build sugar.

The liver uses energy for gluconeogenesis; she consumes fat in the process.

Gluconeogenesis And The Muscles

Our liver does a little bit of gluconeogenesis every day, between meals. She gets the amino acids she needs from the blood. If you've eaten something high in protein, then there are enough amino acid molecules on the move to fuel your brain with sugar until the next meal comes around.

However, if you go on a diet, eat little carbohydrates and force your liver to continuously supply the brain on its own, then it has to produce up to 200 grams of sugar a day. It takes so many amino acids out of the blood that the body has to break down proteins to replenish the amino acid levels.

Unfortunately, humans have no protein stores. The amino acids for gluconeogenesis come from the muscles. The liver of a fasting adult uses about 75 grams of muscle mass per day for gluconeogenesis to ensure the basal metabolic rate.