At the center of the model is a
microfibril (MF) composed of a two-by-two array of elementary fibrils.
Wood quality is also largely affected by its mechanical properties, which are determined by the orientation of cellulose
microfibrils in secondary cell wall, and mechanical strength [4].
Resolution provided by the SEM shows that concentric
microfibrils compose the pit border (Figure 11).
Microtubule-mediated control of
microfibril deposition: a re-examination of the hypothesis.
One possible answer came from Lynn Sakai and coworkers in 1986, when they discovered the major protein of the
microfibril. Sakai named this protein fibrillin.
It occurs frequently in polyurethanes, since the urethane groups have the interactivity and the spatial configuration to generate the aggregation of functional groups to form a kind of
microfibril whose modulus of elasticity is considerably greater than the most flexible part of the molecule (e.g., polyethyleneglycol).
A hypothesis is presented where the combination of a thin cell wall and large
microfibril angle are responsible for the superior properties exhibited by the DN 30 pulp.
It is characterized by shorter cells, larger
microfibril angles, more compression wood, different specific gravity and higher lignin content (Zobel and van Buijtenen, 1989).
Eleven protofibrils form a
microfibril which bundle together into macrofibrils and fill each hair cell.
Collectively, relationships between cell expansion and husk leaf development and function could be speculated as follows: assuming that a certain amount of polysaccharides is required for expansion of a cell, during rapid husk leaf expansion before silking, matrix polysaccharides like hemicellulose and cellulose as well as
microfibril cellulose increase, causing the husk leaf to expand.