Question

Name the bacteriolytic enzyme present in tears.

Answer 1

Hint: Tears are the colorless, watery fluid that is present in the eye. The tears are also known as lacrimal fluid and are secreted by a group of structures known as the lacrimal apparatus. The lacrimal gland produces and secretes the tears with the help of 6-12 ducts that open onto the surface of the conjunctiva of the upper lid.
The primary function of the tears is to keep the surface of the eyeball moist which helps in its movement and focusing. Tears also contain certain bacteriolytic enzymes that resist infection.

Complete answer:
The bacteriolytic enzyme present in the lacrimal fluid or tears is lysozyme.
This enzyme was first isolated and discovered by Alexander Fleming in 1921.
The enzyme actually causes lysis of the carbohydrate chains present in the cell wall of certain bacteria which eventually breaks their structure and ultimately causes death. E.g., Coccus.
Although it should be noted that lysozyme does not prevent the eye from all types of bacterial infections. Those bacteria which have a high lipid concentration in their cell walls are resistant to the lysozyme enzyme and may cause infection.

Note:
The lysozyme is also found in the nasal mucus region, in egg white, and, in the GIT (In the GIT, very trace amounts are found). This is because the lacrimal fluid that is produced in the eye drains into the sinuses through the canal of Schlemm. This canal is present between the junction of cornea and sclera and is also known as scleral venous sinus. When we become emotional or we cry, we experience a runny nose. This is because excess of lacrimal fluid is produced and it drains into the sinus and nasal passage.