Which of the following factors gives the elastin molecule the ability to stretch and recoil?

Ans. B. Cross-links between lysine residuesElastin is an elastic protein found in lungs, dermis, large arteries, ligaments, vocal cords and the ligamentum flavum. Its ability to stretch is conferred by interchain crosslinks between lysine residues.Similar to collagen, elastin is synthesized in several steps. It begins as a large precursor molecule, tropoelastin. Tropoelastin is secreted into the extracellular matrix, where it interacts with Fibrillin-containing microfibril scaffolds to form elastic fibers. The lysine residues on separate elastin molecules interact in a process called desmosine cross-chain linking, providing elastin with its stretch.