Question

Bacterial protein present in human tears is
A. Opsin
B. Retinene
C. Transduction
D. Lysozyme

Answer 1

Hint: Let us first understand what is meant by bacterial protein. Bacterial proteins are the most powerful toxins for human beings. They belong to two categories of lipopolysaccharides or Gram negative bacteria and proteins that are released from the cells of bacteria.

Complete answer:
The tear components have antimicrobial functionalities that include lysosome, lipocalin, lactoferrin, secretory immunoglobulin A (IgA) and complements. Alexander fleming was the first person to show the presence of lysosome in human tears and also to kill Gram positive bacteria. Lysosome enzymes are secreted by the accessory and main lacrimal glands. They constitute about 20% to 30% of total protein.

Opsin: it is a light sensitive protein that is present in the photoreceptor cells in the retina of the eyes. They are the G-protein coupled receptors (GPCRs). In humans there are nine opsins. Three colours in our vision i.e., red, blue and green are determined by the three opsins that are present in the cone photoreceptor cells.
Retinene: it is also called retinal that is chemically derivative vitamin A. In association with opsin, rentinene forms a visual purple pigment known as rhodopsin.
Transduction: it is a process in which the foreign DNA is introduced in the cell by the virus.

Hence, the correct answer is option (D)

Note: Tears protect the eye from external irritants and also by coating the surface of the eye dryness of the eye is prevented. The blood vessels are absent on the surface of the eye, so the tears help in transportation of nutrients and oxygen to the surface cells.