[ CHEMISTRY IN EVERYDAY LIFE ]
NCERT 12TH STD________________________________________________________________________________________________________________________________________________________________________________________
IntroductionChemistry - 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) - interact with macro molecular targets produce
biological response. higher dose
if therapeutic & useful
called medicines.
used in
diagnosis / prevention / treatment of diseases. (Chemotherapy). potential poisons Classification Basis Pharmacological effect for treatment of various types of problems
Eg. Analgesic: pain killers Antiseptic: kill / arrest - growth of organisms.
Drug Action Chemical structure Molecular targets
action of a drug on a particular biochemical process.
drugs with similar chemical structure are grouped - often have similar p.effect
drugs targetting the same class of targets (Eg. (CH, lipids, proteins, nucleic acids))
Eg. Histamine
Eg. Sulphonamides have common structure: causes inflammation in body Antihistamines-inhibit their action. generally shown by drugs possessing some common structural features.
Drug - target interaction
Macromolecules (MM) of biological origin perfom
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
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, VdwF
or dipole-dipole interaction).
The enzyme - may provide FGs - that attack the substrate for a chem. rxn.(b) 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:
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:neurons
communication by
neurons
chemical messengers
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).
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.
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 said Tu-ga-mate
Rani T(a)i
So, beautiful that jaan take
to remove here acidity - then they dine(d)
bro(o) on p ir's hen NH . Ki allergy gone m 2 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 pron zid
phene l zine nor dil
(am) (ia) to - leads me to depression - to come out I use neither a (y) bottle ka .
This was an eg. of tranquilisers - used for treatment of stress, irritability or excitement - by inducing a sense of well - being
Other tranquilisers: Chlordiazepoxide and meprobamate : mild tranquilisers for releasing tension.
Equanil: to control depression and hypertension.
mnemonics:
Chamlor diaz - was tensed - O me went and her proba m atel I .
Equal (ni) l
depression 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 ica visited i , it ated, lives of every d whose lives were nothing but till then, but now under her hypnotism, they fell asleep
Veron Am ty lumin secon nembu
barbaric
(b) Analgesics Non - narcotic (non-addictive) 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 byAspirin. (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 Narcotic
Antimicrobials
Diseases in humans/animals caused by variety of micro organisms:
They are destroyed/inhibited devp. by anti microbial drugs:
bacteria virus fungi
other pathogens / parasites
anti bacterial drugs anti viral agents anti fungal agents anti parasitic drugs
Antibiotics, Antiseptics and disinfectants - antimicrobial drugs. (a) Antibiotics
treat infections - have low toxicity for humans and animals.
Originally - they were - chemical substances - produced by micro organisms (bacteria, fungi, molds) - inhibit / destroy - micro org.
Now - synthetic methods to develop them and also some purely synthetic cmps 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 PaulEhlrich - to discover arsphenamine (salvarsan) - (Arsenic based) - to treat syphilis. It affects humans too - but bacteria, spirochete more so.
Ehlrich noted SalvarsanSimilarity inStructure Azodyes
AsAsreplaced byNN
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..
mnemonics:
Silver’s son - being as phine as amine Chat spir - s ally as he see phili ss p 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. Narrow spectrum Broad spectrum Kill/inhibit a wide range of Gram–+ve Gram–ve bacteria. mainly against either Gram +ve or Gram –ve bac.
Limited spectrum 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.
Learning Aids (Antibiotics)
Amin penny cide
gluco of lux Asin side
e - having no - committed sui and in his grave became se ( ) on .
As all became - they were ... thrown towards e f .
tetra cycles static er
chlorin evicol
2G spectrum Raja enicillin
Ampicillin/Amoxycillin 3G spectrum Raja
- was given p G - but that didn't help - So, SC ordered which made him .
Of lux Asin chlorine fevicol Van
com
- was tied with and driven to a pany to talk on 3G spectrum.
Daisy - a ofm ji 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.
Egs:
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% I in R – OH + H O)2 2
applied on wounds. Iodoform - DO -
Boric acid (aq) Weak antiseptic for eyes.
Disinfectants: applied to inanimate objects like floors, drainage systems.
Egs: same as antiseptic but in varying concentration.
antiseptic disinfectant. 0.2% 1% phenols Cl2 (0.2 – 0.4 ppm) (aq) SO2 in low conc.
Learning aid: Dettol
Bithionol I have wounds
When I am bored, I put boric acid in my eyes.
terpine oil and a xylo with Chlorine and Alchol. for bathing
: :
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 ethynyl extra di-ol.
No Vest roll
war fought with or , its fought with in a .
CHEMICALS IN FOOD
Introduction
Chemical - added in food for appeal enhancement (like looks) preservation.
nutritive value.
Colours
Main categories:
Flavours & sweeteness
Fat emulsifiers and stabilizing agents (surface chemistry)
To increase shelf life
Flour improvers-antistaling agents & bleaches.
(or)
Antioxidants
Cosmetic purposes
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 excreted as such harmless. Esp. useful for diabetic people.
entirely inert
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.
Learning aid
Sacch Rina == rtho ulpho enz mide. (O ! SBI)O S B I 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 (C6H5COONa) - 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).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 Egs”
SO2
Sulphites (Na2SO3, 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
Two types of detergents
Soaps
Synthetic detergents
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.
(esters of fatty acids) hydrolyse NaClcolloidal
soap
precipitated soap
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.Soap types Toile t Floating Soap Tran sparent Sha vin g Scouting Soap Soap powder L aun d ry Soa p chips Medicated Soap Granu les
Contain glycerol - to prevent drying rosin (a gum) is added - forms sodium rosinate - lathers well.
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: Na CO (or) Na PO ( 2 3 3 4 make soap act rapidly). dried miniature
soap bubbles
Contain Sodium rosinate Sodium sillicate Sodium carbonate Borax
by running a thin sheet of melted soap on a cool cylinder - scrap off in places substances of
medicinal value (and deodorants) are added.
Why do soaps not work in Hard water?
Hard water (HW)
containsCa
2and
Mg
2.
When soap is dissolved, the following rxn takes place:
2
C H COONa CaCl
17 35
2
2
NaCl
C H COO
17 35
2Ca
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.Non-ionic Cationic Anionic
Anionic detergents (AD)
Sodium salts of sulphonated long chain alcohols or HC.
Prep: long chain alcohols2 4
Conc. H SO
Alkyl Hydrogen Sulphate
Alkyl benzene sulphonic acid NaOH
NaOH
Anionic detergent.
Anionic part - involved in cleansing action.
Use : household work, toothpastes.Cationic detergents (CD)
quarternary ammonium salts of amines with CH COO , Cl , Br as anions3
Cationic part: long HC chain and
on N.
The following CD is used in hair conditioners: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 essential