fibril

Fibril is a fine fiber approximately 1 nm in diameter.

Cytoplasmic fibrils are observed on the protoplasmic cylinders found in most spirochetal species, although no function of the cytoplasmic fibrils has been ascribed.

Polysaccharides, the union of several linked monosaccharides, sometimes serve as a structural compound. Cellulose, the most abundant organic compound on Earth, forms cable-like strings, known as fibrils in the tough walls that enclose plant cells. While cellulose is a compilation of glucose monomers, they form unbranched, long strands instead of coils like starch or glycogen. These are arranged in parallel lines which form on top of each other in an intricate layer through hydrogen bonding.