Vitamin C assists in the synthesis of a protein that is a critical component of all connective tissues in the body, known as what?

Collagen.

Explanation:

Vitamin C is necessary for the synthesis and conservation of collagen, a protein that functions as a kind of ''glue'', joining the cells together. Its constitution is mainly fibrous, providing body structure and support. The resistant, connective and elongated fibers of collagen are present in the skin, ligaments, tendons, cartilage, bones, blood vessels, intestines and in the discs that separate the vertebrae of the spine. The role of vitamin C in the production of collagen is to interact with the amino acids within its cells. Vitamin C adds hydrogen and oxygen to these amino acids, stimulating the production of collagen.