(a) Which of the following is disinfectant?

0-2% solution of phenol or 1% solution of phenol

(b) What is the difference between agonists and antagonists?

(c) Write one example each of:

(i) Artificial sweetener

(ii) Antacids

OR

Define the following terms with a suitable example of each:

a) Antiseptics

b) Bactericidal antibiotics

c) Cationic detergents

S

(a) 0.2 per cent solution of phenol is an antiseptic while its one percent solution is disinfectant.

(b) Drugs that bind to the receptor site and inhibit its natural function are called antagonists.

Agonists mimic the natural messenger by switching on the receptor.

(c) (i) Example of Artificial sweetener is Saccharin (Ortho-sulphobenzimide).

(ii) Example of Antacids is sodium hydrogencarbonate.

OR

a) Antiseptics are applied to the living tissues such as wounds, cuts, ulcers and diseased skin surfaces. Examples are furacine, soframicine, etc. Commonly used antiseptic, dettol is a mixture of chloroxylenol and terpineol. Bithionol (the compound is also called bithional) is added to soaps to impart antiseptic properties. Iodine is a powerful antiseptic. Its 2-3 per cent solution in alcohol water mixture is known as tincture of iodine. It is applied on wounds. Iodoform is also used as an antiseptic for wounds. Boric acid in dilute aqueous solution is weak antiseptic for eyes.

b) Bactericidal antibiotics are those which have cidal (killing) effect. Examples are Penicillin, Aminoglycosides and Ofloxacin.

c) Cationic detergents are quarternary ammonium salts of amines with acetates, chlorides or bromides as anions.

Cationic part possesses a long hydrocarbon chain and a positive charge on nitrogen atom. Hence, these are called cationic detergents.

Cetyltrimethyl ammonium bromide is a popular cationic detergent and is used in hair conditioners. Cationic detergents have germicidal properties.