CHAPTER 19: Unit 3. Types of Proteins: Secondary Structures

The protein secondary structures are formed when hydrogen bonds are formed within a single polypeptide.

There are two types of secondary structures:

1. Alpha Helix
2. Beta – Pleated Sheet

The video below illustrates the secondary structure of protein:

The figure below exhibits the secondary structure of protein:

Reference: https://www.researchgate.net/figure/Dierent-hierarchical-structures-in-proteins-a-Primary-structure-Polypeptide-chain_fig15_258020421

Alpha helix is made of proteins connected in a spiral and helical shape through hydrogen bonding in alpha position as shown in the figure above.Beta sheet is made of proteins connected in sheet shape through hydrogen bonding in beta position as shown in the figure above.

Primary structure of protein is shown as combined alpha and beta structures:

Reference: https://www.khanacademy.org/science/biology/macromolecules/proteins-and-amino-acids/a/orders-of-protein-structure

Secondary protein structure can be converted into an intermediate before it folds spontaneously. Secondary protein structure is used in multiple sequence alignment which is used in RNA production.Example of secondary protein structure is Collagen.Collagen is the most abundant protein in the human body. It makes the protein of blood, vessel, skins, tendons, ligaments, the cornea of the eyes and cartilages and gastrointestinal tract.Collagen is made triple helix.The figure of collagen is given below:

Reference: https://www.123rf.com/photo_110228993_stock-vector-collagen-fiber-molecule-and-amino-acid-sequence-molecular-structure-three-polypeptides-coil-to-form-.html