Intracellular sources glycogen

All muscle types require ATP to achieve contraction. Glucose, fatty acids and amino acids may all be used as oxidizable substrates to produce ATP and all three energy sources may be obtained from stored intracellular sources (glycogen, triglyceride and protein) or imported from the blood stream. In quantitative terms, skeletal muscle is... 

Each glucose monomer derived from glycogen gives rise to 36 ATP molecules to provide the immediate energy source for functions such as muscle contraction, nucleic acid syntheses, protein synthesis, and maintaining the proper intracellular environment and extracellular matrix. 

The principal pathway for the fermentation of glucose and fructose is the Embden-Meyerhof-Parnas route (alternatively named EMP or glycolytic sequence). Wort sucrose is hydrolysed extracellularly and maltose and maltotriose intracellularly. Intracellular storage carbohydrates such as glycogen and trehalose may also serve as sources of intracellular monosaccharide. 

Alpha-D-glucans (glycogen, amylose and amylopectin) are usually intercellular back-up sources of energy and cells building blocks. At the same time, beta-D-glucans are related to structural intracellular polysaccharides. 

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