Chemistry · Ch 14 — Biomolecules
Classification of Proteins
Classification of Proteins
Proteins are classified, based on their overall structure (shape), into two major types: fibrous proteins and globular proteins.
Fibrous proteins are linear molecules, similar in shape to fibres. They are generally insoluble in water and are held in that extended shape by disulphide bridges and weak intermolecular hydrogen bonds. Because of their linear, rope-like architecture, fibrous proteins are typically used as structural proteins in the body -- keratin (found in hair, nails and skin) and collagen (found in connective tissue, skin and bone) are the two examples given. …
What this figure shows. A schematic of a fibrous protein drawn as long, roughly parallel polypeptide strands running side by side in an extended, rope-like arrangement, cross-linked at intervals by disulphide bridges and hydrogen bonds -- the linear architecture that makes fibrous proteins like keratin and collagen suited to a s …
What this figure shows. A schematic of a globular protein drawn as a single polypeptide chain folded and coiled compactly into an overall spherical/globular mass, in visual contrast to the extended fibrous protein of Figure 14.15(a) -- the compact, water-soluble architecture that makes globular proteins like myoglobin and insulin suited to functiona …