A key step for producing biofuels using biochemical platform is the enzymatic hydrolysis. Enzymatic depolymerization of the insoluble cellulose involves the cellulase action in the removal of the glucose chains from the surface of the crystalline cellulose. Therefore, molecular level understanding of the properties of cellulose that provide resistance to the depolymerization will be helpful in removing the bottlenecks in the enzymatic hydrolysis process. This work deals with investigation of the “non-reaction” factors, which affect the above hydrolysis reaction. To understand the behavior of the substrate – enzyme – water systems, initially, the energetics of the depolymerization of the insoluble cellulose were investigated using molecular dynamic simulations. Simulation results are used to quantitatively determine the non-reaction resistances in terms of the interfacial structure, diffusion in the system and free energy requirements for the separation of chains in the crystalline cellulose. Free energy calculations performed on the polysaccharide chains showed an increase in the interchain attractive interactions in presence of water. The structuring of water around the cellulose and the enzyme action on the surface of the cellulose are also discussed.