Which of the following statements about collagen is true?
It is part of a family of lipoproteins found only in extracellular matrix.
It is the single most abundant protein in both animals and plants.
It has a rod-like triple helix structure.
None of these are true statements.
All of these are true statements.
The Correct Answer and Explanation is :
The correct statement is: “It has a rod-like triple helix structure.”
Explanation:
Collagen is the main structural protein in the extracellular matrix of various connective tissues in animals. It is the most abundant protein in mammals, constituting 25% to 35% of the total protein content in the body.
Collagen molecules are characterized by a rod-like triple helix structure. Each collagen molecule consists of three polypeptide chains, known as alpha chains, which are wound around each other to form a right-handed triple helix. This unique structure provides collagen with its tensile strength and stability, making it a crucial component of connective tissues such as skin, tendons, ligaments, and bones.
The other statements are incorrect:
- “It is part of a family of lipoproteins found only in extracellular matrix.” This statement is inaccurate. Collagen is a fibrous protein, not a lipoprotein. Lipoproteins are complexes of lipids and proteins that transport lipids in the blood. Collagen, on the other hand, is primarily found in the extracellular matrix of connective tissues.
- “It is the single most abundant protein in both animals and plants.” This statement is incorrect. While collagen is the most abundant protein in mammals, it is not present in plants. In plants, the most abundant protein is ribulose-1,5-bisphosphate carboxylase-oxygenase (RuBisCO), which plays a key role in photosynthesis.
In summary, collagen’s rod-like triple helix structure is fundamental to its function as a structural protein in connective tissues. The other statements about collagen are not accurate.