Proteins are organic macromolecules made up of linear chains of amino acids. However, while a protein’s basic structure is a linear amino acid chain, the final structure of a protein is not linear. Instead, the protein’s amino acid sequence—and the physical and chemical properties of the amino acids and of the entire protein molecule - influences how it folds into a three dimensional shape.
The amino acid sequence of a protein is determined by the base pair sequence in the gene which codes for the protein. There are twenty ‘standard’ amino acids (along with one or two non-standard proteins which are not coded for by DNA in the usual sense).
These are less ‘active’ than those involved in catalyzing reactions, signaling cells, and transporting molecules, but are no less important.
- Structural proteins are those which confer strength and rigidity to biological components which would otherwise be unable to support themselves.
- Structural proteins tend to have very specific shapes—long, thin fibers or other shapes which, when allowed to form polymers, provide strength and support.
- Structural proteins are essential components of collagen, cartilage, nails and hair, feathers, hooves, and other such components.
- Structural proteins are also essential components of muscles, and are necessary to generate the force which allows muscles to contract and move.
Here is a list of some related reading covering a variety of topics on how protein plays a part in health, protein function, protein sources, and more on the role protein plays in the human body.