Chemistry in Everyday Life

[ CHEMISTRY IN EVERYDAY LIFE ] NCERT 12TH STD

________________________________________________________________________________________________________________________________________________________________________________________ Introduction Chemistry - ubiquitous in every part of our lives: Cleanliness - soap, detergents , tooth pastes. Clothes - synthetic fibres, colours by chemicals. Food - made up of org/inorg chemicals. Medicines - chemicals Explosives, fuels, rocket propellants, building & electronic material, human beings themselves and their control by various chemicals. Drugs and their clarification Drugs - chemicals of low molecular masses (~ 100 - 500 u) produce - interact with macro molecular targets   biological response.

higher dose if therapeutic & useful

potential poisons

called medicines. used in diagnosis / prevention / treatment of diseases. (Chemotherapy). Classification Basis

Pharmacological effect  for treatment of various types of problems

Drug Action

Chemical structure

 action of a drug on a particular biochemical process.

 drugs with similar chemical structure are grouped - often have similar p.effect

Molecular targets  drugs targetting the same class of targets (Eg. (CH, lipids, proteins, nucleic acids))

Eg. Analgesic: pain killers Eg. Histamine Antiseptic: kill / arrest Eg. Sulphonamides have  generally shown causes growth of organisms. common structure: by drugs possessing inflammation some common in body structural features. Antihistamines-inhibit their action.

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Drug - target interaction perfom Macromolecules (MM) of biological origin   various functions in body..

Eg. Proteins - biological catalysts - enzymes. - crucial to communication system - receptors. - carry polar molecules across membranes - Carrier proteins Nucleic Acids

- coded genetic information of the cell.

lipids and CH

- structural parts of cell membrane. Enzyme as drug targets

(a)

Catalytic action of enzymes



(b)

enzymes are selective catalysts. i.e. they catalyse rxn only of a specific shape of reagents:



Here, as can be seen - the enzyme holds the substracts in a suitable position - can be attacked by reagent now. (the binding is achieved by - IB, HB, Vdw F or dipole-dipole interaction).



The enzyme - may provide FGs - that attack the substrate for a chem. rxn.

Drug - enzyme interaction



Drugs inhibit activities of enzyme - by blocking the binding site or inhibiting the catalytic activity of enzyme - called enzyme inhibitors.

2 ways:



Competitive inhibitors: They have same shape as substrate and compete with it to block the enzyme:

( Shorthand Notation : w/ means with ; w/o means without ; wh/ means which ) 2



Attacking allosteric site: Some drugs attack a site (allosteric site) other than the active site - forming bond with enzyme - rendering the enzyme to change shape of active site - and so, substrate can’t recognise it - and enzyme is blocked (esp. if covalent bond is formed w/ drug wh/ can’t be broken easily). - in such cases, body degrades this “enzyme - inhibitor” complex and synthesises a new enzyme.

Non-competitive inhibitor changes the active site of enzyme after binding at allosteric site. Receptors as drug targets



Receptors: proteins crucial to body’s communication process - embedded in cell membranes as shown below:

–

a small part of RP (receptor proteins) - projects out of the surface of the membrane and opens on the outside region.



In body:

communication by neurons  chemical messengers   neurons

neurons   muscles 

received at binding sites of RP - shape of RP changes as CM is received - this transfers the message into the cell (so, msg conveyed by CM w/o entering the cell).

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

Different RP - interact - different CM - show selectivity due to different shape, structure and amino acid composition.



Antagonists: drugs that bind to RP - inhibit its natural function (used when blocking of msg is required).



Agonists: mimic the natural messenger by switching on the receptor (used when there is a lack of natural messenger).

Therapeutic Action of Different Classes of Drugs



Antacids: NaHCO3 (or) Al(OH)3 /Mg(OH)2 - react with excess acid produced in stomach (wh/ if unchecked - develop into ulcers) - but excess HCO3 makes the stomach alkaline can trigger production of even more acid. But M(OH) x - insoluble - don’t increase pH above neutrality - So, better.

 Control only symptoms - not good in treatment - and in advance stages when ulcers become life threatening - only treatment is operating and removing affected part of the stomach.



Anti histamines (AHM): Histamines (HM) - stimulate secretion of pepsin and HCl - in stomach - by interacting with receptors present in stomach wall. Some drugs - prevent interaction of HM w/ RP  lesser secretion of acid. Egs: Cimetidine (Tegamet) and ranitidine (Zantac):

 So, these are AHM that act as antacids. Vasodilator - relaxes muscles like in the walls of blood vessels - contracts smooth muscles in bronchi and gut. HM is a vasodilator. HM - also responsible for - nasal congestion associated w/ common cold and allergic response to pollen. Other AHM (synthetic) - brompheniramine (Dimetapp) and terfenadine (Seldane):

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Act by - competing w/ HM for binding sites of receptor where HM exerts its effect. So, these AHMs are anti-allergic. (But why do these not act as antacids too? - because antiallergic and antacid drugs work on different receptors.

Mnemonics: C(o)i met hits Rani T(a)i to remove here acidity - then they dine(d) said Tu-ga-mate

So, beautiful that jaan take

bro(o)m on p ir's

hen  NH2. Ki allergy gone  hen was so happy

that it went to a tap(p) and paid a dime to use it. Terfe na(g)dine in Selem ka dane because of her allergy

Neurologically Active drugs (a) Tranquilizers -

affect msg transfer mechanism from nerve to receptor.



Nor adrenaline (mnemonics: Nor - blood rushing - adrenaline). - a neurotransmitter - role in mood changes. - if low - signal sending activity is also low  results in depression - to counter - anti depressants are required - they inhibit enzymes wh/ catalyse the degradation of noradrenaline -then, it is slowly metabolised and activates its receptors  depression gone. Drug Egs: Iproniazid and phenelzine (Nardil). (fig. below):

mnemonics: I (am) pron (ia) to zid - leads me to depression - to come out I use neither a phene(y)l bottle ka zine nor dil.



This was an eg. of tranquilisers - used for treatment of stress, irritability or excitement - by inducing a sense of well - being

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 Other tranquilisers:  

Chlordiazepoxide and meprobamate : mild tranquilisers for releasing tension. Equanil: to control depression and hypertension.

mnemonics: Chamlor diaz

O

- was tensed - me went and her probalm I ate.

depression Equal (ni) l hypertension

 Derivatives of barbituric acid - called barbiturates - (veronal, amytal, nembutal, luminal, seconal) - imp. class of tranquilisers- are hypnotic - sleep producing agents. 

Other Egs. of tranquilisers: Valium, Serotonin.

mnemonics: When Veronica visited Amity, it luminated, lives of every second nembu whose lives were nothing but barbaric till then, but now under her hypnotism, they fell asleep All Sher with Valour are brought down using tranquilisers

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Non - narcotic (non-addictive)

(b) Analgesics

Narcotic

 reduce pain w/o causing consciousness impairment, mental confusion, incoordination or paralysis or some other disturbance of nervous system. 

Non-narcotic: Eg. Aspirin and paracetamol.



Aspirin:

prostagladins - stimulate inflammation tissue-cause pain.

 its creation stopped by Aspirin. (esp. for skeleton pain due to arthritis, reduce fever (antipyretic), prevent platelet coagulation)



Also, has anti blood clotting action  used in prevention of heart attacks.



Narcotic: Eg. Morphine and its homologues (Eg. Heroin, Codeine.)

   

When given in medicinal doses - relieve pain and produce sleep in poisonous doses - stupor, coma, convulsions, ultimately death. called opiates (as obtained from opium poppy). used also for : post operative pain, cardiac pain, pains of terminal cancer, in child birth.

Learning aid:

Analgesics

Non-narcotic

Aspirin

Narcotic

Paracetamol

Heroin(e) took morphine in a codeine

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Antimicrobials

Diseases in humans/animals caused by variety of micro organisms:

They are destroyed/inhibited devp. by anti microbial drugs:

bacteria

anti bacterial drugs

virus

anti viral agents

fungi

anti fungal agents

other pathogens / parasites

anti parasitic drugs

Antibiotics, Antiseptics and disinfectants - antimicrobial drugs. (a)

Antibiotics

 

treat infections - have low toxicity for humans and animals.



Now - synthetic methods to develop them and also some purely synthetic cmp s have been found to have antibacterial properly - So, modified def: produced wholly/partly by chemical synthesis - wh/inhibit / destroy micro org. - by intervening in their metabolic process.



19th century - search for chemicals - that adversely affect bacteria - but not host - led Paul Ehlrich - to discover arsphenamine (salvarsan) - (Arsenic based) - to treat syphilis. It affects humans too - but bacteria, spirochete more so.



 Azodyes     As  As  replaced by  N  N    Ehlrich noted Salvarsan  Structure also, tissues getting coloured by dyes selectively  search for - cmps structurally similar to azodyes and selectively bind to bacteria - led to  prontosil, first effective anti bacterial agent



Prontosil - in body, converted to - sulphanil amide - which is the actual acting part - led to  a large no. of sulphonamide analogues - called sulpha drugs, collectively.. One of the most effective sulpha drugs: Sulpha pyridine



Originally - they were - chemical substances - produced by micro organisms (bacteria, fungi, molds) - inhibit / destroy - micro org.

Similarity in

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mnemonics: Silver’s son - being as phine as amine - Chats spirally as he sees philips TV Salvarsan - azodye - prontosil - sulph anil amide - sulph on amide analogues sulpha drugs - sulph a pyridine. (connect as a story). 

Alexander Fleming - discovered - Penicillium fungus - took 13 yrs. in trials  penicillin.



Antibiotics - cidal (killing) effect or

Static (inhibitory) effect





Bactericidal



Bacteriostatic

Penicillin

Erythromycin

Aminoglycosides

Tetracycline

Ofloxacin

Chloram phenicol

Spectrum of action: range of bacteria/micro organisms that are affected by a certain antibiotic.

Broad spectrum

Narrow spectrum

Limited spectrum

Kill/inhibit a wide range of Gram–+ve Gram–ve bacteria.

mainly against either Gram +ve or Gram –ve bac.

if active against a single organism/ disease. Eg. Penicillin G synthetic modification broad spectrum



Ampicillin Amoxycillin.

Penicillin - may be allergic -  , needs to be tested for before being administered. (Mfg: Hindustan antibiotics at Pimpri). [Note: Gram - staining is a method of differentiating bacterial species into two large groups: Gram positive & Gram negative. It is based on the chemical/physical properties of the cell walls. Primarily it detects peptidogly can, which is present in a thick layer in Gram positive bacteria. A Gram +ve results in a purple/blue colour while a Gram negative results in a pink/ red colour].



Broad spectrum antibiotics:



Chloramphenicol:

rapidly from gastro intestinal tract - So, given orally in case of typhoid, dysentry, acute fever, certain urinary infections, meningitis and pneumomia.



Vancomycin and ofloxacin



Dysidazirine: supposed to be toxic towards certain strains of cancer cells.

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Learning Aids (Antibiotics) Amine - having no penny - committed suicide and in his grave became glucose of lux (Asin) on side. As all tetra cycles became static - they were er ... thrown towards chlorine fevicol. 2G spectrum Raja - was given p enicillin G - but that didn't help - So, SC ordered Ampicillin/Amoxycillin which made him 3G spectrum Raja. Of lux Asin - was tied with chlorine fevicol and driven to a Van company to talk on 3G spectrum. Daisy - maji of rin - was diagnosed with cancer

(b)

Antiseptics and disinfectants (kill/prevent growth-micro organisms)  Antiseptics  applied to living tissues (wounds, cuts, ulcers, diseased skin surfaces) - not ingested.  Eg s :

Antiseptic

Purpose

Furacine

 multi purpose

Soframicine

 multi purpose

Dettol (terpineol + chloroxylenol)

 common wounds, shaving

Bithionol (or Bithional)

 added to soaps for antiseptic properties.

Tincture of Iodine (2-3% I2 in R – OH + H2O)

 applied on wounds.

Iodoform



Boric acid (aq)

 Weak antiseptic for eyes.

- DO -

 Disinfectants: applied to inanimate objects like floors, drainage systems.  Egs : same as antiseptic but in varying concentration.

0.2%



phenols

1%

antiseptic disinfectant.



Cl2 (0.2 – 0.4 ppm) (aq)



SO2 in low conc.

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Learning aid: :

Dettol

Bithionol :

terpine oil and a xylo with Chlorine and Alchol. for bathing

I have wounds When I am bored, I put boric acid in my eyes. Antifertility drugs 

Antibiotics - long and healthy life - life expectancy doubled  presence on food resources, unemployment, etc. - to counter these - population needs to be planned - family planning antifertility drugs - a step in that direction.



Birth control pills - (synthetic estrogen + progesterone derivatives) - both cmps - are hormones - progesterone - suppresses ovulation - its synthetic versions are more potent.



Nore thin drone - Eg. of progesterone derivative.



ethynylestradiol (nonvestrol) - Eg. of estrogen derivative.

Learning Aid: P (register one)  Nor thin neither drone Is trojan war fought with ethynyl extra or di-ol. No, its fought with Vest in a roll.

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CHEMICAL S IN FOOD Introduction preservation. Chemical - added in food for

appeal enhancement (like looks) nutritive value.

Colours Flavours & sweeteness Main categories:  To increase shelf life Fat emulsifiers and stabilizing agents (surface chemistry)  (or) Flour improvers-antistaling agents & bleaches. Cosmetic purposes Antioxidants  Preservatives

Natrutive value  Nutritional supplements  minerals,vits,amino acids  Artificial Sweetening Agents

 

Natural sweeteners (Eg. Sucrose) - high calories -  , many avoid it. Artificial sweetener:

Sweetener

Sweetness compared to cane sugar

Remarks

Saccharin (Ortho-sulpha benzimide)

550

  entirely inert  excreted as such    harmless. Esp. useful for diabetic people.

Aspartame

100

  aspartic acid + phenylalanine  dipeptide   its methyl ester Aspartame (Unstable at cooking temperature  So, use ltd. to cold foods and soft drinks).

Alitame

2000

 high potency (strength) sweetener - more stable than aspartame - but control of sweetness is difficult.

Sucrolose

600

  Sucrose  trichloro derivative - appears and tastes like sugar - stable at cooking temp.

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Learning aid Saccha Rin == Ortho Sulpho Benz Imide. (O ! SBI) As per tom  Aspartame is sweet Ali tamed his over - sweet behaviour. Su Cro?  lose weight Food preservatives (prevent spoilage of food due to microbial growth).



Egs:

  

Salt (table), sugar Vegetable oils Sodium Benzoate (C 6 H5 COONa) - used in ltd. quantity - metabolised in the body

(Metabolism: Your metabolism is the way that chemical processes in your body cause food to be used in an efficient way, for example to make new cells and to give you energy).



Salts of sorbic acid and propanoic acid

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Antioxidants

 Food decomposes by oxidation - Antioxidants (AO) - retard the action of Oxygen on food - reducing its speed of decomposition  food preservation.  They act by virtue of being more reactive towards oxygen than are the materials they are protecting.  Also, reduce rate of involvement of free radicals in ageing process.



Egs :



added to preserve fats in packaged food - by - Oxygen reacting preferably with them. their addition to butter - increases storage life from months to years. Sometimes added with citric/ascorbic acids to produce a more active synergetic effect.



Other Eg s ”

 

SO 2 Sulphites (Na 2 SO3 , NaHSO3 , sodium meta bisulphite) both are used for



beer & wine

 

Sugar syrup Cut, peeled or dried fruits and vegetables Prevent / reduce their discolouration

Questions:

 

Name one AO commonly used to increase the storage life of butter. Name one AO used in wine and beers.

CLEANSING AGENTS Introduction Soaps



Two types of detergents Synthetic detergents

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improve cleansing property of water.  by helping in removal of fats wh/ bind other materials to the fabric/skin

Soaps Preparation (called saponification): fat + NaOH (aq)  soap.



Chemically, they are Na/K salts of long chain fatty acids, eg. stearic, oleic and palmitic acids.



hydrolyse NaCl (esters of fatty acids)   soap   precipitated soap colloidal

 when removed glycerol left behind (recovered by F.D.)



K soaps - softer than Na Soaps. - prepared by using KOH instead of NaOH in the above.

Types of soaps Gen. prep: fats / oils + suitable hydroxide  variations by using different raw mat.

Contain Sodium rosinate Sodium sillicate Sodium carbonate Borax

vin

g

ps

y

c hi

Sha

ap

ndr

substances of medicinal value (and deodorants) are added.

So

Lau

by running a thin sheet of melted soap on a cool cylinder - scrap off in places

Contain glycerol - to prevent drying rosin (a gum) is added - forms sodium rosinate - lathers well.

il To

et

Floating Soap Tra es ns p nul a r are G p nt Soa Soap Scouting powder Soap Medicated

Soap types

dried miniature soap bubbles

better grade fat/oil excess alkali must be removed added colour & perfumes

by beating tiny air bubbles before hardening

by dissolving soap in ethanol (then evaporate the solvent)

scourging agent (abrasive) Eg. powdered pumice/ finely divided sand Buiders: Na2CO3 (or) Na3PO4 (  make soap act rapidly).

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 Why do soaps not work in Hard water? contains Ca 2  and Mg 2  . When soap is dissolved, the following rxn  Hard water (HW)  takes place:

2C17 H 35COONa  CaCl2  2 NaCl   C17 H 35COO  2 Ca  Insoluble Calcium Stearate 

 An insoluble cmp. ppt. out - separate as scum - useless as cleaning agent - further - sticks to clothes as a gummy mass.  Thats why hair washed with HW - looks dull.  Thats why dye - doesn’t absorb evenly on cloth washed in hard water. Synthetic detergents



all properties of soap - but don’t contain soap - can be used in hard water as well and even in ice cold water.

Anionic

Non-ionic

Cationic

Anionic detergents (AD)



Sodium salts of sulphonated long chain alcohols or HC.



Prep: 

Conc.

 Alkyl Hydrogen Sulphate long chain alcohols  H 2SO 4

 NaOH 

 

Alkyl benzene sulphonic acid

NaOH  

Anionic detergent.

Anionic part - involved in cleansing action. Use : household work, toothpastes.

Cationic detergents (CD)



   with quarternary ammonium salts of amines   CH 3COO , Cl , Br as anions



Cationic part: long HC chain and  on N.



The following CD is used in hair conditioners:

 Have germicidal properties and are expensive 16

Non-ionic detergents (NID)

 No ions  An example:  Use: Liquid dishwashing  Mechanism of action: Same as soaps. (ie. by micelle formation) Problem w/ detergents



if HC part - highly branched  bacteria can’t degrade it  leads to their accumulation they reach water bodies as such  cause foaming in water bodies and thus pollutes them.



Solution: branching of HC is kept at a minimum.

Learning Aid: 

Soap : Steer using palm oil  Na/K salts



AD: Long chain alcohol/HC (sulphonated)   Na salts.



CD : Quaternary ammonium salts of Amines with A B C as anions.

END NOTE Chemistry is essentially the study of materials and the development of new materials for the betterment of

humanity. A drug is a chemical agent, which affects human metabolism and provides cure from ailment. If taken in doses higher than recommended, these may have poisonous effect. Use of chemicals for therapeutic effect is called chemotherapy. Drugs usually interact with biological macromolecules such as carbohydrates, proteins, lipids and nucleic acids. These are called target molecules. Drugs are designed to interact with specific targets so that these have the least chance of affecting other targets. This minimises the side effects and localises the action of the drug. Drug chemistry centres around arresting microbes/destroying microbes, preventing the body from various infectious diseases, releasing mental stress, etc. Thus, drugs like analgesics, antibiotics, antiseptics, disinfectants, antacids and tranquilizers are used for specific purpose. To check the population explosion, antifertility drugs have also become prominent in our life. Food additives such as preservatives, sweetening agents, flavours, antioxidants, edible colours and nutritional supplements are added to the food to make it attractive, palatable and add nutritive value. Preservatives are added to the food to prevent spoilage due to microbial growth. Artificial sweeteners are used by those who need to check the calorie intake or are diabetic and want to avoid taking sucrose. These days, detergents are much in vogue and get preference over soaps because they work even in hard water. Synthetic detergents are classified into three main categories, namely: anionic, cationic and non-ionic, and each category has its specific uses. Detergents with straight chain of hydrocarbons are preferred over branched chain as the latter are non-biodegradable and consequently cause environmental pollution.

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