Chemistry in Everyday Life Notes | Chemistry Class 12 Chapter 15 | STAR tube Notes

Chapter 15
Chemistry in Everyday Life

Chemistry in Everyday Life 

Higher Secondary is the most crucial stage of school education because at this juncture specialized discipline

based, content  ‐oriented courses are introduced. Students reach this stage after 10 years of general

education and opt for Chemistry with a purpose of pursuing their career in basic sciences or professional

courses like medicine, engineering, technology and study courses in applied areas of science and technology

at tertiary level. Therefore, there is a need to provide learners with sufficient conceptual background of

Chemistry, which will make them competent to meet the challenges of academic and professional courses

after the senior secondary stage.

1.Drugs : Drugs are chemical of low molecular masses, which interact with
macromolecular targets and produce a biological response.

2.Chemotherapy :The use of chemicals for therapeutic effect is called chemotherapy.

3.Classification of Drugs :

(i)On the basis of pharmacological effect : Drugs for a particular type of problem as analgesics for pain relieving.

(ii)On the basis of drug action : Action of drug on a particular biochemical process.

(iii)On the basis of chemical action : Drugs having similar structure, e.g.,sulpha drugs.

(iv)On the basis of molecular targets : Drugs interacting with biomolecules as lipids, proteins.

4.Enzymes as Drug Targets :

(i)Catalytic action of enzymes :

 (a)Enzymes have active sites which hold the substrate molecule. It can be attracted by reacting molecules.
 (b)Substrate is bonded to active sites through hydrogen bonds, ionic bonds, van der Waal or dipole-dipole interactions.

(ii)Drug-enzyme interactions :

 (a)Drug complete with natural substrate for their attachments on the active sites of enzymes. They are called competitive inhibitors.
 (b)Some drugs binds to a different site of the enzyme called allosteric sites which changes the shape of active sites.

5.Antagonists : The drugs that bind to the receptor site and inhibit its natural function.

6.Agonists : Drugs mimic the natural messenger by switching on the receptor.

7.Antacids : These are compounds which neutralize excess acid of stomach. E.g.,
Aluminium hydroxide, magnesium hydroxide, rantidine, cimetidine.

8.Anti Histamines : The drugs which interfere with the natural action of histamines and prevent the allergic reaction. E.g., Rantidine, Bromphenisamine, seldone.

9.Tranquilizers : The class of chemical compounds used for the treatment of stress, mild or even severe mental diseases. E.g., depression, Iproniazid, Phenelzine
(antidepressant), chlordiazeopoxide, meprobamati (mild tranquilizes), veronal,
amytal, seconal, equamil.

10.Analgesics : They reduce pain without causing impairment of consciousness,
mental confusion or some other disturbance of the nervous system. E.g., Aspirin, seridon, phenacetin.

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11.Antimicrobials : They tend to prevent/destroy or inhibit the pathogenic action of microbes as bacteria, virus, fungi etc. They are classified as :

(i)◆Antibiotics : Those are the chemical substances which are produced by
micro-organisms. E.g., Penicillin, Ofloxacin.

    ◆Narrow spectrum antibiotics : These are effective mainly against gram positive or gram negative bacteria. E.g., Penicillin, streptomycin.

    ◆Broad spectrum antibiotics : They kill or inhibit a wide range of micro-organisms. E.g., Chloramphenicol, tetracycline, amoxycillin, ampicillin, oflexauin, vancomyain.

(ii)Antiseptics or Disinfectant : These are which either kill/inhibit the growth of micro-organisms.

Antiseptics are applied to the living tissues such as wounds, cuts, ulcers etc.

E.g., Furacine, chloroxylenol and terpinol (dettol). Disinfectant are applied to inanimate objects such as floors, drainage system.

E.g., 0.2% solution of phenol is an antiseptic while 1% solution of phenol is an disinfectant.

12.Antifertility drugs : These are the chemical substances used to control the
pregnancy. They are also called oral contraceptives or birth control pills. E.g.,
Mifepristone, norethindrone.

13.Artificial Sweetening Agents : These are the chemical compounds which give sweetening effect to the food without adding calorie. They are good for diabetic
people. E.g., Aspartame, saccharin, alitame, sucrolose.

14.Food Preservatives : They prevents spoilage of food to microbial growth. E.g.,
Salt, sugar and sodium benzoate.

15.Antioxidants : They help in food preservation by retarding the action of oxygen on food. e.g., Butylated hydroxy toluene (BHT) Butylated hydroxyanisole (BHA), SO2, sulphite used as antioxidant for wine and beer.

16.Cleansing Agents :

(i)Soaps : They are sodium or potassium salts of fatty acids. They are obtained by the saponification reaction, when fatty acids are heated with aqueous sodium hydroxide. They do not work well in hard water.

(ii)Toilet soaps : That are prepared by using better grade of fatty acids and excess of alkali needs to be removed. Colour and perfumes are added to make them attractive.

(iii)Medicated soaps : Substances or medicinal value are added. E.g., Bithional,
dettol.

17.Synthetic Detergents : They are cleaning agents having properties of soaps, but actually contain no soap. They can be used in both soft and hard water.
They are :

(i)Anionic detergents : They are sodium salts of sulphonated long chain alcohols or hydrocarbons.
E.g., Sodium lauryl sulphonate.
They are effective in acidic solution.
 CH3
(CH2
)CH2
OH → CH3
(CH2
)10CH2
OSO3
H → CH3
(CH2
)10CH2
OSO3
−Na+
 (lauryl alcohol) (sodium lauryl sulphonate)

(ii)Cationic detergents : They are quarternary ammonium salts of amines
with acetates, chlorides or bromides.
They have germicidal properties
and expensive used in hair conditioners CH3
(CH6
)16COO(CH2
CH2
O)
n
CH2
CH2
OH.
E.g., cetyltrimethylammonium bromide.

(iii)Non-ionic detergents : They do not contain any ions. Some liquid dishwashing detergents are of non-ionic type.

18.Biodegradable Detergents : The detergents which are linear and can be attacked by micro-organisms are biodegradable.
E.g., Sodium 4-(1-dodecyl) benzene/sulphonate.

19.Non-biodegradable Detergents : The detergents which are branched and cannot
be decomposed by micro-organisms are called non-biodegradable.
E.g., Sodium 4-(1, 3, 5, 7 tetramethyloctyl-benzene sulphonate.
It creates water pollution.

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