AP BIOLOGY

Detailed explanation-1: -Collagen is an abundant structural protein in all animals. In humans, collagen comprises one-third of the total protein, accounts for three-quarters of the dry weight of skin, and is the most prevalent component of the extracellular matrix (ECM).

Detailed explanation-2: -Collagen is protein molecules made up of amino acids. It provides structural support to the extracellular space of connective tissues. Due to its rigidity and resistance to stretching, it is the perfect matrix for skin, tendons, bones, and ligaments.

Detailed explanation-3: -Type I collagen is the most abundant collagen found in connective tissues including skin, tendon, and bone tissue.

Detailed explanation-4: -Collagen is principal protein of the skin, tendons, ligaments, cartilage, bone, and connective tissue.

Detailed explanation-5: -The most abundant protein in connective tissue is collagen, but it also contains various other proteins (such as elastin, fibronectin, and laminin) and proteoglycans in varying proportions, depending on the organ.