Q. What is tertiary structure of a protein? What are the major types of tertiary structure?

The tertiary protein structure is a spatial conformation additional to the secondary structure in which the beta-sheet or the alpha- helix folds itself up.

The forces that keep the tertiary structure generally are interactions between the -R groups of the amino acids and between other parts of the water and protein molecules of the solution.

The main types of tertiary structure of proteins are the fibrous proteins and the globular proteins.