Question

After you eat a donut the carbohydrate needs to be digested, absorbed and carried in the blood to the brain. Explain what's going to happen to your donut to get some glucose to the brain.

Answer 1

Once you eat a dough nut, which mainly contains carbohydrates, they are broken down mechanically by the action of chewing, The saliva secreted from your salivary glands moistens food as it's chewed. Saliva releases an enzyme called amylase, which begins the breakdown process of carbohydrates into sugar. When carbohydrates reach the stomach no further chemical breakdown occurs because the amylase enzyme does not function in the acidic conditions of the stomach, digestion of carbohydrates tekes pllace primarily in the small intestine by the action of various enzymes, the wall of the small intestine begins to make lactase, sucrase, and maltase these enzymes break down the carbohydrates even further into monosaccharides or single sugars, These sugars are the ones that are finally absorbed into the small intestine, some of these sugars are converted to stored form of glucose known as glycogen by the liver, the remaining part of sugar or glucose are absorbed into the blood stream, from the blood stream special transporter molecults takes these sugar molecules to the brain. Glucose or sugar is the primary energy substrate of the brain,  Glucose from blood enters the brain by a transport protein. Glucose transport protein (GLUT-1) is highly enriched in brain capillary endothelial cells. tese transporters carry glucose molecules through the blood brain barrier to the brain, the brain typically gets most of its energy from oxygen-dependent metabolism of glucose.