Main source of energy in 1min is
Why body stores glucose as glycogen and not as glucose itself? Possible Reasons 1. Being insoluble it exes no osmotic pressure, and so does not disturb the intracellular fluid content and does not diffuse from its storage sites. 2. It has a higher energy level than a corresponding weight of glucose (though energy has to be expended to make it from glucose). 3. It is readily broken down under the influence of hormones and enzyme: * Into glucose in liver (to maintain blood glucose level). * Into lower intermediates in skeletal muscle and other tissues for energy. Role of Liver Glycogen * It is the only immediately available reserve store of blood glucose. * A high liver glycogen level protects the liver cells against the harmful effects of many poisons and chemicals, e.g. CCl4, ethyl alcohol, arsenic, various bacterial toxins. * Ceain forms of detoxication, e.g. conjugation with glucuronic acid; and acetylation reactions, are directly influenced by the liver glycogen level. * The rate of deamination of amino acids in the liver is depressed as the glycogen level rises so that amino acids are preserved longer in that form and so remain available for protein synthesis in the tissues. * Similarly, a high level of liver glycogen depresses the rate of ketone bodies formation. Biomedical Impoance * Liver glycogen is largely concerned with storage and supply of glucose-1-P, which is conveed to glucose, for maintenance of blood glucose, paicularly in between meals. * Muscle glycogen on the other hand, is to act as readily available source of intermediates of glycolysis for provision of energy within the muscle itself. Muscle glycogen cannot directly contribute to blood glucose level. * Inherited deficiency of enzymes in the pathway of glycogen metabolism produces ceain inherited disorders called as Glycogen storage diseases (GSD)Ref: MN Chatterjea Textbook of Medical Biochemistry, 8th edition, page no: 346
Glycogen
FFA
Phosphates
Glucose
Respiratory chain