The article from PubMed titled "Biochemistry, Collagen Synthesis" discusses the vital role of collagen, a protein composed of amino acids, in providing structural support to connective tissues. It highlights that collagen is crucial for the integrity of skin, tendons, bones, and ligaments due to its rigidity and resistance to stretching. The article further explains that there are various types of collagen, with types I through IV being the most common, and type I comprising over 90% of collagen in the human body. For a more detailed understanding of the topic, please refer to the full article on PubMed.