Question

Protein present in eye lens is
A. Opsin
B. Collagen
C. Crystallin
D. Rhodopsin

Answer 1

Hint: The protein present in the eye lens is responsible for the transparent or crystal-like appearance of the eye lens.

Step by step answer:
In option A, opsin is mentioned. Opsin protein is a transmembrane protein present in the cone cells. They are activated when a photon of light enters the eye and activates the chromophore molecule, a retinal, embedded in the opsin. So, this protein is found in the retina.
In option B, collagen is mentioned. Collagen is the protein found in the human body the most. It is found in bones, muscles, skin, and tendons. It is the protein that binds the parts of the body together and holds it.
In option C, crystalline is mentioned. Crystallin is a structural and water-soluble protein. It is found in the eye lens and the cornea of the eye. This protein is the reason for the transparency of the eyes.
In option D, rhodopsin is mentioned. Rhodopsin is the protein found in the rods of the retina and is a G-protein-coupled receptor (GPCR). It belongs to the class of opsin proteins. Rhodopsin protein is highly sensitive to light. This is the protein responsible for vision in low-light.
So, the correct option is option C.

Note: The lenses in the eyes are built of long cells, this means crystalline cells are elongated. The cells are deprived of cell nuclei and mitochondria. This leaves the protein to be a smooth and transparent solution. The crystalline proteins are of three types: alpha, beta, and gamma. The crystalline solutions in the eyes are the mixture of all three.