Question

Collagen fibres are found maximum in
A. Ligaments
B. Tendons
C. Bone
D. Cartilage

Answer 1

Collagen is the substance that holds the body together and it is the main component of connective tissues. It is most abundantly found in mammals. It has a triple helix structure and there are mainly $5$ types of collagen found in the body.

Complete answer: Collagen is the most abundant protein in mammals and is found in the extracellular matrix of connective tissues. There are five most common types of collagen found in the body: type$1$ present in the skin, tendons and bone; type $2$ present in the cartilage; type $3$ present in reticular fibres; type $4$ present in the basement membrane or basal layer of the epithelium, and type $5$ present in hair, placenta. 90% of collagen is type $1$ collagen. The structure of collagen is made up of fibrils that are in turn made up of collagen molecules called tropocollagen. $3$ polypeptides coil to form tropocollagen. Collagen makes $60\%$ of the dry weight of cartilage and about $90\%$ of matrix proteins in bone are collagen. The bone is more hard and dense than that of the cartilage because it has more collagen fibres in its matrix.
Hence option C is the correct answer.

Note: Collagen has a triple-helix structure that has two identical chains called alpha $1$ and a third chain, which is slightly different in a chemical composition called alpha $2$ chains. Hydrogen bonds between these three chains give structural stability and strength to collagen. It shows great tensile strength and it can only be broken down via enzymatic activity in the body.