(a) Amylose typically consists of 200–1000 D-glucopyranoside units connected in α -linkages between C1 of one unit and C4 of the next. Water-insoluble amylopectin has a structure similar to that of amylose [i.e., α(1→4) links] with the exception that in amylopectin the chains are branched.
(b) The bond connecting the amino acids in a protein is commonly called a peptide linkage or peptide bond. The peptide linkage is an amide bond formed between −COOH group and −NH2 group.
Polysaccharides, also known as glycans, consist of monosaccharides joined together by glycosidic linkages. (c) Fibrous proteins exist as long fibers or strings stabilized by hydrogen and disulphide bonds. They run parallel to each other. These proteins, including myosin (in muscles), collagen (in skin) and keratin (in hair), are usually tough and water insoluble. Globular proteins are spherical in shape, highly folded and tend to be water soluble. The common examples are albumins and insulin.
