Which of the following are intracellular events occurring in fibroblast during synthesis of collagen?

C. Collagen helix It is a triple helical structure found in collagen (details in Chapter 52). 3. Teiary Structure i. Secondary structure denotes the configurational relationship between residues which are about 3-4 amino acids apa; or secondary level defines the organization at immediate vicinity of amino acids. The teiary structure denotes three-dimensional structure of the whole protein (Box 4.1 and Fig. 4.8). The teiary structure defines the steric relationship of amino acids which are far apa from each other in the linear sequence but are close in the three-dimensional aspect. ii. The teiary structure is maintained by noncovalent interactions such as hydrophobic bonds, electrostatic bonds, and van der Waals forces. The teiary structure acquired by native protein is always thermodynamically most stable. iii. Domain is the term used to denote a compact globular functional unit of a protein. A domain is a relatively independent region of the protein and may represent a functional unit. The domains are usually connected with relatively flexible areas of protein (see immunoglobulins, Chapter 49). Phenylalanine hydroxylase enzyme contains 3 domains, one regulatory, one catalytic and one protein-protein interaction domains.Ref: DM Vasudevan - Textbook of Biochemistry, 6th edition, page no: 31