Organic Chemistry Basics: Hydrocarbons, Biomolecules, Polymers, Drugs

Organic chemistry and biomolecules are reliable Kerala PSC topics. Questions focus on functional groups, polymer names, vitamins/deficiency diseases, and drug classifications. Expect 2-4 questions per Graduate Level paper.

1. Hydrocarbons — Classification

Type	General Formula	Bonding	Examples
Alkanes (Paraffins)	CnH2n+2	Single bonds only (saturated)	Methane (CH4), Ethane (C2H6), Propane (C3H8)
Alkenes (Olefins)	CnH2n	One double bond (unsaturated)	Ethene/Ethylene (C2H4), Propene (C3H6)
Alkynes	CnH2n-2	One triple bond (unsaturated)	Ethyne/Acetylene (C2H2)
Aromatic	—	Benzene ring (alternating bonds)	Benzene (C6H6), Toluene, Naphthalene

First 10 Alkanes (PSC Favourite)

No. of Carbons	Name	Formula
1	Methane	CH4
2	Ethane	C2H6
3	Propane	C3H8
4	Butane	C4H10
5	Pentane	C5H12
6	Hexane	C6H14
7	Heptane	C7H16
8	Octane	C8H18
9	Nonane	C9H20
10	Decane	C10H22

Important Hydrocarbons

Compound	Key Fact
Methane	Simplest hydrocarbon; major component of natural gas; “marsh gas”
Ethylene (Ethene)	Fruit ripening agent; simplest alkene
Acetylene (Ethyne)	Used in oxy-acetylene welding; simplest alkyne
Benzene	Simplest aromatic compound; carcinogenic; discovered by Faraday
LPG	Mainly Butane + Propane mixture
CNG	Mainly Methane (compressed)

2. Functional Groups

Functional Group	Formula	Class of Compound	Example
Hydroxyl (-OH)	-OH	Alcohol	Methanol (CH3OH), Ethanol (C2H5OH)
Aldehyde (-CHO)	-CHO	Aldehyde	Formaldehyde (HCHO), Acetaldehyde
Ketone (C=O)	-CO-	Ketone	Acetone (CH3COCH3)
Carboxyl (-COOH)	-COOH	Carboxylic Acid	Acetic acid (CH3COOH), Formic acid
Amino (-NH2)	-NH2	Amine	Methylamine, Amino acids
Ester (-COO-)	-COO-	Ester	Ethyl acetate (fruity smell)
Ether (-O-)	-O-	Ether	Diethyl ether (anaesthetic)

Common Organic Compounds for PSC

Common Name	Chemical Name	Formula	Use
Vinegar	Acetic acid (dilute)	CH3COOH	Food preservative
Formalin	40% Formaldehyde solution	HCHO	Preserving biological specimens
Wood spirit	Methanol	CH3OH	Industrial solvent (poisonous)
Grain alcohol	Ethanol	C2H5OH	Beverages, fuel, antiseptic
Acetone	Propanone	CH3COCH3	Nail polish remover, solvent
Chloroform	Trichloromethane	CHCl3	Formerly anaesthetic
Carbolic acid	Phenol	C6H5OH	Disinfectant

3. Polymers

Polymer	Monomer	Type	Use
Polyethylene (PE)	Ethylene	Addition	Carry bags, bottles, pipes
Polypropylene (PP)	Propylene	Addition	Packaging, automotive parts
PVC (Polyvinyl Chloride)	Vinyl chloride	Addition	Pipes, cables, flooring
Polystyrene	Styrene	Addition	Thermocol, disposable cups
Teflon (PTFE)	Tetrafluoroethylene	Addition	Non-stick cookware
Natural Rubber	Isoprene	Addition (natural)	Tyres, erasers
Nylon 6,6	Hexamethylene diamine + Adipic acid	Condensation	Textiles, ropes, toothbrush bristles
Terylene (Dacron/PET)	Ethylene glycol + Terephthalic acid	Condensation	Polyester fabric, bottles
Bakelite	Phenol + Formaldehyde	Condensation	Electrical switches, handles
Melamine	Melamine + Formaldehyde	Condensation	Crockery, laminates

Natural vs Synthetic Polymers

Natural Polymers	Synthetic Polymers
Cellulose, Starch	Polyethylene, PVC
Proteins	Nylon, Terylene
Natural rubber	Synthetic rubber (Neoprene, Buna-S)
DNA, RNA	Bakelite, Teflon
Silk, Wool	Rayon (semi-synthetic)

4. Biomolecules — Carbohydrates

Type	Examples	Key Fact
Monosaccharides (simple sugars)	Glucose (C6H12O6), Fructose, Galactose	Cannot be hydrolysed further
Disaccharides	Sucrose (table sugar), Lactose (milk sugar), Maltose (malt sugar)	Yield 2 monosaccharides on hydrolysis
Polysaccharides	Starch, Cellulose, Glycogen	Yield many monosaccharides; not sweet

Important Fact	Detail
Glucose	”Blood sugar”; C6H12O6; energy source for cells
Fructose	Sweetest natural sugar; found in fruits
Sucrose	Glucose + Fructose; table sugar from sugarcane
Lactose	Glucose + Galactose; milk sugar
Starch	Storage polysaccharide in plants
Glycogen	Storage polysaccharide in animals (“animal starch”)
Cellulose	Structural polysaccharide in plant cell walls; most abundant organic compound

5. Biomolecules — Proteins

Aspect	Detail
Building blocks	Amino acids (20 standard amino acids)
Bond connecting amino acids	Peptide bond (-CO-NH-)
Elements present	C, H, O, N, S
Functions	Enzymes, structural (keratin, collagen), transport (haemoglobin), immunity (antibodies)
Denaturation	Loss of shape/function by heat or acid (e.g., cooking egg)

Important Proteins

Protein	Role
Haemoglobin	Oxygen transport in blood
Insulin	Blood sugar regulation (hormone)
Keratin	Structural — hair, nails, feathers
Collagen	Structural — skin, tendons, bones
Antibodies	Immune defence
Enzymes	Biological catalysts (pepsin, amylase, lipase)

6. Biomolecules — Lipids (Fats and Oils)

Aspect	Detail
Composition	Glycerol + 3 Fatty acids (triglycerides)
Saturated fats	Solid at room temperature; animal fats (butter, ghee)
Unsaturated fats	Liquid at room temperature; plant oils (coconut oil exception: saturated but liquid in warm climate)
Functions	Energy storage, insulation, cell membrane component
Cholesterol	Steroid lipid; needed for hormones; excess causes heart disease

7. Vitamins — The Complete Table

Vitamin	Chemical Name	Source	Deficiency Disease
A	Retinol	Carrot, liver, fish oil	Night blindness (Nyctalopia), Xerophthalmia
B1	Thiamine	Whole grains, pork	Beri-Beri
B2	Riboflavin	Milk, eggs, green vegetables	Cheilosis (cracked lips)
B3	Niacin	Meat, peanuts, mushrooms	Pellagra (3 Ds: Dermatitis, Diarrhoea, Dementia)
B5	Pantothenic acid	Meat, eggs, broccoli	Fatigue, numbness
B6	Pyridoxine	Bananas, potatoes, chicken	Anaemia, skin disorders
B7	Biotin	Eggs, nuts, soybeans	Dermatitis, hair loss
B9	Folic Acid	Leafy greens, legumes	Megaloblastic anaemia; neural tube defects in foetus
B12	Cyanocobalamin	Meat, fish, dairy (NOT in plants)	Pernicious anaemia
C	Ascorbic Acid	Citrus fruits, amla, guava	Scurvy (bleeding gums, loose teeth)
D	Calciferol	Sunlight, fish, eggs	Rickets (children), Osteomalacia (adults)
E	Tocopherol	Nuts, seeds, vegetable oils	Infertility, muscle weakness
K	Phylloquinone	Green leafy vegetables, liver	Delayed blood clotting

Fat-Soluble vs Water-Soluble Vitamins

Fat-Soluble (stored in body)	Water-Soluble (not stored; need daily intake)
A, D, E, K	B-complex (B1–B12), C

8. Drugs — Classification

Category	Examples	Action
Analgesics (painkillers)	Aspirin, Paracetamol, Ibuprofen, Morphine	Relieve pain
Antibiotics	Penicillin, Streptomycin, Tetracycline	Kill/inhibit bacteria
Antipyretics	Paracetamol, Aspirin	Reduce fever
Antiseptics	Dettol (Chloroxylenol), Iodine tincture	Applied on wounds
Disinfectants	Phenol, Bleach (NaOCl)	Applied on non-living surfaces
Anaesthetics	Diethyl ether, Chloroform, Nitrous oxide	Loss of sensation
Antihistamines	Cetirizine, Promethazine	Counter allergic reactions
Antacids	Milk of Magnesia (Mg(OH)2), Aluminium hydroxide	Neutralise stomach acid
Tranquillisers	Valium, Barbiturates	Reduce anxiety

PSC Favourite Drug Facts

Fact	Detail
First antibiotic	Penicillin (Alexander Fleming, 1928)
Aspirin chemical name	Acetylsalicylic acid
”Laughing gas”	Nitrous oxide (N2O) — anaesthetic
Antiseptic vs Disinfectant	Antiseptic = on living tissue; Disinfectant = on non-living objects
Insulin discovered by	Banting and Best (1921)

9. GMO and Biotechnology in Chemistry Context

Term	Detail
Fermentation	Anaerobic breakdown of sugar by yeast → Ethanol + CO2
Biodiesel	From vegetable oils/animal fats; transesterification process
Biogas	Methane-rich gas from decomposition of organic waste
Bioplastics	Made from renewable biomass (starch, cellulose); biodegradable

10. PSC Quick Recall Table

Question	Answer
Simplest hydrocarbon?	Methane (CH4)
LPG is mainly?	Butane + Propane
Non-stick coating material?	Teflon (PTFE)
First antibiotic?	Penicillin (Fleming, 1928)
Night blindness caused by deficiency of?	Vitamin A
Scurvy caused by deficiency of?	Vitamin C
Rickets caused by deficiency of?	Vitamin D
Beri-Beri caused by deficiency of?	Vitamin B1 (Thiamine)
“Animal starch”?	Glycogen
Sweetest natural sugar?	Fructose
Protein in hair and nails?	Keratin
Oxygen carrier in blood?	Haemoglobin
Most abundant organic compound on Earth?	Cellulose
Formalin is solution of?	Formaldehyde (40%)
Vinegar contains?	Acetic acid
Nylon is which type of polymer?	Condensation polymer
Fat-soluble vitamins?	A, D, E, K
Pellagra is caused by deficiency of?	Vitamin B3 (Niacin)