which carbohydrate does the body use for energy production during respiration
Carbohydrate metabolism Although humans consume a variety of carbohydrates, digestion breaks down complex carbohydrates into a few simple monomers (monosaccharides) for metabolism: glucose, fructose, and galactose.[4] Glucose constitutes about 80% of the products, and is the primary structure that is distributed to cells in the tissues, where it is broken down or stored as glycogen.[3][4] In aerobic respiration, the main form of cellular respiration used by humans, glucose and oxygen are metabolized to release energy, with carbon dioxide and water as byproducts.[2] Most of the fructose and galactose travel to the liver, where they can be converted to glucose.[4]
Glycogen As a meal containing carbohydrates or protein is eaten and digested, blood glucose levels rise, and the pancreas secretes insulin. Blood glucose from the portal vein enters liver cells (hepatocytes). Insulin acts on the hepatocytes to stimulate the action of several enzymes, including glycogen synthase. Glucose molecules are added to the chains of glycogen as long as both insulin and glucose remain plentiful. In this postprandial or "fed" state, the liver takes in more glucose from the blood than it releases.
Rate equation k is the first order rate constant, which has units of 1/s or sâˆ’1.
Glycogen Approximately 4Â grams of glucose are present in the blood of humans at all times;[2] in fasted individuals, blood glucose is maintained constant at this level at the expense of glycogen stores in the liver and skeletal muscle.[2] Glycogen stores in skeletal muscle serve as a form of energy storage for the muscle itself;[2] however, the breakdown of muscle glycogen impedes muscle glucose uptake, thereby increasing the amount of blood glucose available for use in other tissues.[2] Liver glycogen stores serve as a store of glucose for use throughout the body, particularly the central nervous system.[2] The human brain consumes approximately 60% of blood glucose in fasted, sedentary individuals.[2]