Explain the following terms giving one example of each type: (i) Antacids (ii) Disinfectants

(i) Antacids: Chemical substances which remove excess acid in the stomach and raise the pH to appropriate level, e.g., sodium hydrogencarbonate, a mixture of aluminium and magnesium hydroxide, ranitidine, etc.

(ii) Disinfectants: These are the chemical substances which kill microorganisms or stop their growth but are harmful to human tissues, e.g., phenol (1%), chlorine in concentration of 0.2 to 0.4 pm in aqueous solution, SO₂ , etc

(iii) Enzymes: Enzymes are globular proteins with high molecular mass ranging from 15,000 to 1,000,000 g mol^–1, which form colloidal solution in water. A number of reactions that occur in the body of animals and plants to maintain the life processes are catalyzed by enzymes, therefore enzymes are termed as biochemical catalysts.