Q: Compare and contrast the structure of collagen and cellulose

The monomer of collagen is an amino acid whereas the monomer of cellulose is beta-glucose. The monomers in collagen are linked by peptide bonds whereas those of cellulose are beta (1,4)-glycosidic bonds. Collagen is an alpha helix polypeptide with a turn every three residues whereas cellulose is a straight chain with adjacent glucose molecules rotated 180 degrees with respect to each other. Collagen has hydrogen bonds between its chains (glycine on one chain and hydroxyproline on another strand), these hydrogen bonds account for its strength. Likewise, cellulose is a strong material because of the hydrogen bonds between the -OH and O of adjacent molecules. Collagen's macrofibre structure is that of triple helices lying parallel with covalent bonds at staggered ends of carboxyl and amino terminal, thus forming collagen fibre; in cellulose, chains of beta-glucose associate in groups to form micelles, micelles arrange in larger bundles to form microfibrils. Microfibrils combine by cross-linking of chains to form macrofibrils. Both collagen and cellulose are resistant to chemical change because of their stable macro structure