16. CHEMISTRY IN EVERYDAY LIFE
Q. 1. Why do we need to classify drugs in different ways ?
Ans.
analgesics have pain killing effect, whereas antiseptic kill or arrest the growth of microorganisms.
Q. 2. Explain the term, target molecules or drug targets as used in medicinal chemistry.
Ans. Traget molecules or drug targets : Drugs usually interact with biological macromolecules such as carbohydrates, lipids proteins and nucleic acids. These biological molecules are called targets. The correct choice of the molecular target for a drug is important to obtain its disired therapeutic effect.
Q. 3. Name the macromolecules that are chosen as drug targets.
Ans. Macromolecules that are chosen as drug targets include carbohydrate, lipids, proteins and nucleic acids.
Q. 4. Define the term Chemotherapy.
Ans. Use of chemicals in prescribed doses for – therapeutical effect is called Chemotherapy.
Q. 5. What is meant by the term ‘broad soectrum antibiotics’ ? Explain.
Ans. The full range of microorganisms attacked by an antibiotic is called its spectrum. Broad spectrum antibiotics are medicines effective against several different types of harmful microorganisms, e.g., tetracycline, chloramphenicol and a mixture of potent antibiotics.
Q. 6. Name a substance which can be used as an antiseptic as well as disinfectant.
Ans. 0.2 percent solution of phenol is an antiseptic while its one percent solution is disinfectant.
Q. 7. What are main constituents of dettol ?
Ans. Dettol is a mixture of chloroxylenol and terpineol in a suitable solvent.
Q. 8. What is tincture of iodine ? What is its use ?
Ans. It is 2-3% solution of iodine in alcohol and water. It is a powerful antiseptic.
Q. 9. What are food preservatives ?
Ans. Food preservatives prevent spoilage of food due to microbial growth. Table salt, sugar and vegetable oils are class I preservatives. The most common preservative of class II is sodium benzoate (C6H5COONa]. It can be safely used in small quantities which is metabolised in body.
Q. 10 . How are synthetic detergents better than soap ?
Ans. Soaps when used in hard water from curdy precipitate that separates as scum. These insoluble soaps are useless as cleanising agent. Synthetic detergents, on the other hand, can be used in any sort of water because they form foam even in water containing mineral compounds. Some of them can give foam even in ice cold water.
Q. 11. Why do soaps not work in hard water?
Ans. Hard water contains calcium and magnesium ions. These form insoluble calcium and magnesium soaps respectively.
2 C17H35COONa + Ca Cl2 → 2 NaCl + (C17H35COO)2Ca
(Calcium chloride Insoluble calcium
in hard water) stearate (soap)
These insoluble soaps are useless as cleansing agent. In fact these are hindrance to good washing because this precipitate adheres on to the fibres of the cloth as gummy mass.
Q. 12. Why do we require artificial sweetening agents ?
Ans. Natural sweetners like glucose, sucrose etc. add to calorie intake and therefore many people prefer to use artificial sweetners. They area of great value to diabetic persons and people who are calorie-conscious. They are excreted from the body in the urine unchanged.
Q. 13. How do antiseptics differ from disinfectants ? Give one example of each.
Ans. Antiseptics are the chemicals which either kill or prevent the growth of micro-organisms without affecting the living human tissues. Disinfectants also kill the micro-organism and also affect the living human tissues. Example of :
(i) antiseptic : Dettol, iodoform
(ii) disinfectants : Chlorine, potassium permanganate.
Q. 14. What are artificial sweetening agents ?
Give two examples.
Ans. The artificial sweeteners are food additives. They do not add calories intake. Examples are (i) Saccharine and (ii) aspartame.
Q.15. Name an alkaloid in each case used for the treatment of (i) hypertension, (ii) malaria fever, (iii) pain.
Ans. (i) Reserpine is the alkaloid used for treatment of hypertension.
(ii) Quinine is the alkaloid used for treatment of malaria.
(iii) Morphine is the alkaloid used for the treatment of pain.
Q. 16. Name the active chemoterapeutic agent in each of the following used medicine : (i) Brufen, (ii) Crocin, (iii) Disprin.
Ans. (i) Brufen :p-Isobutylphenyl-2-propanoic acid.
(ii) Crocin : Paracetamol
(iii) Disprin : Acetylsalicylic acid.
Q. 17. What is an antibiotic ? Give the name of first antibiotic discovered.
Ans. Antibiotics are chemical substances (Produced wholly or partially by chemical synthesis) which in low concentration, either kill or inhibit the growth of microorganisms by intervening in their metabolic process. Pencillin was the first antibiotics discoverd.
Q. 18. Why are detergents preferred to soaps. How are detergents classified ?
Ans. Detergents are preferred to soaps because they work even in hard water as cleanising agents. Detergents are classified in the three categories : (i) Anionic detergents, (ii) Cationic detergents, (iii) Non-ionic detergents.
Q. 19. How do drugs interact with enzymes ?
Ans. Drugs inhibit the activites of enzymes. Such drugs are also called enzyme inhibitors. Enzyme inhibitors can block the binding site and prevent the binding of substrate or these can inhibit the catalytical activity of enzyme.