Chemicals in Everyday Life – Medicines, Food Additives & Cleansing Agents

Vocabulary flashcards summarising key terms and definitions from the lecture on drugs, food additives and cleansing agents.

Drug

A low-molecular-mass chemical that interacts with macromolecular targets to produce a biological response.

Medicine

A drug whose biological response is therapeutic and useful for curing or preventing disease.

Chemotherapy

Branch of chemistry that studies the use of chemicals (drugs) to treat or prevent disease.

Pharmacological-effect classification

Grouping of drugs according to the overall effect they produce (e.g., analgesic, antiseptic).

Drug-action classification

Grouping of drugs by the specific biochemical process they affect (e.g., antihistamines block histamine action).

Chemical-structure classification

Grouping of drugs that share common structural features and often similar activity (e.g., sulfonamides).

Molecular-target classification

Grouping of drugs by the biomolecule—protein, nucleic acid, lipid or carbohydrate—they interact with.

Enzyme inhibitor

Drug that blocks an enzyme’s binding site or catalytic activity, stopping substrate conversion.

Competitive inhibitor

Enzyme inhibitor that competes with the natural substrate for the enzyme’s active site.

Therapeutic Index (TI)

Ratio of maximum tolerated dose to minimum curative dose (MTD/MCD); larger TI = safer drug.

Antacid

Drug that neutralises excess stomach acid and raises gastric pH (e.g., NaHCO₃, Al(OH)₃ + Mg(OH)₂).

Antihistamine

Drug that counteracts histamine to relieve allergies (e.g., diphenylhydramine, chlorpheniramine).

Tranquilizer

Psychotherapeutic drug that alleviates stress, anxiety or mental disorders; common in sleeping pills.

Antidepressant drug

Tranquilizer used specifically to reduce depression (e.g., iproniazid, phenelzine).

Barbiturate

Hypnotic tranquilizer that induces sleep (e.g., seconal, luminal, veronal).

Sedative

Central-nervous-system depressant that produces calmness and drowsiness (e.g., diazepam).

Analgesic

Drug that reduces or abolishes pain.

Non-narcotic analgesic

Non-addictive painkiller, often antipyretic as well (e.g., aspirin, paracetamol).

Narcotic analgesic

Addictive painkiller that also induces sleep (e.g., morphine, heroin, codeine).

Antimicrobial drug

Chemical that destroys, inhibits or prevents the pathogenic action of microbes.

Antibiotic

Antimicrobial substance produced by microorganisms, having bactericidal or bacteriostatic effects.

Bactericidal antibiotic

Antibiotic that kills bacteria outright (e.g., penicillin, amoxicillin, streptomycin).

Bacteriostatic antibiotic

Antibiotic that stops bacterial growth without killing them (e.g., erythromycin, tetracycline).

Antiseptic

Antimicrobial safe for living tissue, applied to wounds or skin (e.g., dettol, iodine, boric acid).

Disinfectant

Antimicrobial used on inanimate objects like floors or drains (e.g., 1 % phenol, chlorine).

Antifertility drug

Synthetic estrogen/progesterone derivative used in birth-control pills (e.g., norethindrone + ethinylestradiol).

Artificial sweetening agent

Low- or zero-calorie substance that replaces sugar to control calories and prevent tooth decay.

Saccharin

o-Sulphobenzimide; first zero-calorie sweetener, 550× sweeter than sucrose.

Aspartame

Dipeptide sweetener (NutraSweet); 200× sweeter than sugar but unstable at high cooking temperatures.

Sucralose

Trichloro derivative of sucrose; heat-stable, sugar-like taste, suitable for diabetics.

Alitame

Very high-potency, heat-stable artificial sweetener, more powerful than aspartame.

Food preservative

Chemical that prevents microbial spoilage of food (e.g., sodium benzoate, sorbic acid salts).

Surfactant

Surface-active agent that concentrates at interfaces, lowers surface tension and emulsifies grease.

Soap

Sodium or potassium salt of a higher fatty acid, produced by saponification of fats or oils.

Saponification

Alkaline hydrolysis of fats/oils yielding soap and glycerol.

Toilet soap

High-quality soap made from better fats with excess alkali removed for skin use.

Transparent soap

Soap dissolved in ethanol and re-solidified to produce a clear bar.

Medicated soap

Soap containing added substances of medicinal value (e.g., antiseptics).

Shaving soap

Soap formulated with glycerol and rosin to give stable lather and prevent rapid drying.

Laundry soap

Soap containing fillers like sodium silicate or borax for enhanced cleaning in washing clothes.

Synthetic detergent

Alkyl benzene sulphonate cleansing agent, also called a syndet.

Anionic detergent

Detergent whose cleansing head carries a negative charge; used in household cleaners and toothpastes.

Cationic detergent

Quaternary ammonium salt detergent with a positive head; used in hair conditioners, germicides.

Non-ionic detergent

Detergent with no ionic charge, often an ester of fatty acid and polyethylene glycol; used in dishwashing liquids.

Biodegradable detergent

Detergent with straight-chain alkyl groups that can be decomposed by microorganisms.

Non-biodegradable detergent

Detergent with branched-chain alkyl groups resistant to microbial decomposition, leading to pollution.

Hard water

Water containing Ca²⁺ and Mg²⁺ ions that form insoluble scum with soaps, reducing cleaning efficiency.