Question

Protein present in cartilage and bone is
A. Chondrin and ossein respectively
B. Chondroitin sulfate
C. Cartilagein
D. None of the above

Answer 1

Hint: Cartilage is a smooth elastic tissue, composed of specialized cells known as chondrocytes. And bone is a rigid growing tissue of a living organism. Collagen is the major structural protein found in structures like cartilage ECM, in bones, hair, nails, skin, connective tissues, and growth plate during endochondral ossification.

Complete answer:
-Cartilage has a bluish-white gelatin-like substance called Chondrin. Chondrin is a gelatin-like protein-carbohydrate substance that forms a matrix in cartilage to embed cartilage cells. Whereas, bones contain collagen proteins known as Ossein. The combination of collagen and calcium makes the bone strong and flexible to withstand stress.
-Bone is composed of several types of cells like osteoblasts, osteocytes, and osteoclasts. On the other hand, cartilage is made of specialized cells called chondrocytes that produce the collagenous extracellular matrix (ECM), which is rich in proteoglycans and elastin fibers.
-Protein chondrin is found in cartilage and protein ossein is present in bones. Hence, option A is the right answer.

Additional Information:
1. There are three kinds of cartilages based on the differences in matrix, cellular arrangement, and function. These are hyaline, elastic, and fibrous cartilage.
2. There are two types of bones: Cortical and trabecular. Cortical is the dense and compact bone that forms the outer layer of the bone and trabecular is a spongy, honey-comb like structure that makes up the inner layer of the bone.
Correct option is ‘Chondrin and ossein respectively’.

Note: The matrix of cartilage is made up of different proteins like glycosaminoglycans, proteoglycans, collagen fibers, and elastin. Chondroitin sulfate is a structural component of cartilage, it’s a chemical and not a protein.