Chemistry in Everyday Life

Chemistry's impact on our lives is profound and pervasive. Chemicals play a vital role, from the cleanliness products we use daily to the clothes we wear and the food we consume. Medicines, synthetic fibres, vibrant colours, and even our bodies are all chemistry products. This unit explores three fascinating realms where chemistry shines: medicines, food materials, and cleansing agents.

1.0How is Chemistry Important in Everyday Life?

Chemistry permeates our daily existence, shaping the food we consume, the fabrics we wear, and even the air we breathe. Its impact is omnipresent, from cooking to textile production and environmental analysis to technological advancements. Chemistry is the invisible force driving innovation and sustainability in our modern world.

2.0Importance of Chemistry in Medicines

Chemicals characterized by low molecular masses, usually falling within the range of approximately 100 to 500 atomic mass units (u), engage with substantial molecular targets within the body, prompting a biological response.  When this response is beneficial for diagnosing, preventing, or treating diseases, these chemicals are termed medicines. Drugs can be classified mainly on criteria outlined as follows:

• Pharmacological Effect: Drugs are classified based on their pharmacological effects, aiding doctors in selecting appropriate treatments. For instance, analgesics relieve pain, while antiseptics inhibit microbial growth.
• Drug Action: Drugs are classified according to how they affect specific biochemical processes. For example, antihistamines block histamine, reducing inflammation.
• Chemical Structure: Drugs with similar chemical structures often share pharmacological activities. For instance, sulphonamides share a common structural feature.
• Molecular Targets: Drugs interact with biomolecules, such as carbohydrates, lipids, proteins, and nucleic acids. Classification based on molecular targets is crucial for medicinal chemists, aiding in understanding mechanisms of action.

Therapeutic Action of Different Classes of Drugs

Various drugs, including antacids, antihistamines, tranquillizers, analgesics, antibiotics, antiseptics, and antifertility/fertility drugs, serve therapeutic purposes. They are commonly utilized to alleviate pain, manage acidity, and address skin irritation, showcasing the widespread application of chemistry in daily healthcare practices.

• Antacids: A breakthrough in treating hyperacidity came with the discovery of histamine's role in stimulating stomach acid secretion. Cimetidine (Tagamet) was designed to block histamine's interaction with stomach receptors, reducing acid production. Initially the best-selling drug, it was later surpassed by ranitidine (Zantac).                  
• Neurologically Active Drugs (NADs) target the transmission mechanism between nerves and receptors. They come in two categories:
•  Tranquillizers: found in sleeping pills, are utilized to alleviate stress and mental disorders. Their effect includes reducing anxiety and stress while helping manage irritability or excitement.
•  Analgesics: are employed to alleviate or diminish pain while minimizing adverse effects like paralysis or mental confusion. They are classified into two: Non-Narcotic and Narcotic drugs.
• Antimicrobials combat infections caused by bacteria, viruses, fungi, and other pathogens. They include:
•  Antibiotics: Synthetic substances like penicillin, discovered by Alexander Fleming, inhibit or kill microorganisms. They're categorized as bacteriostatic (inhibiting growth) or bactericidal (killing bacteria).
•  Antiseptics: These are used to treat wounds, cuts, and skin conditions and are available in ointments or lotions. Examples include Dettol, iodine, iodoform, and boric acid.
• Antifertility drugs, commonly known as birth control pills, contain synthetic progesterone and estrogen, preventing natural pregnancy. These medications are potent and can modify hormone secretion within the body..

Drug-Target Interaction

Biological macromolecules serve diverse functions in the body. Proteins act as enzymes, catalyzing biochemical reactions and as receptors, facilitating communication within the body. Carrier proteins aid in transporting polar molecules across cell membranes. Nucleic acids contain genetic information. Lipids and carbohydrates serve as structural components of cell membranes. Drug-target interactions can be exemplified through enzymes and receptors.

Enzymes: As drug targets

As drug targets, enzymes play crucial roles in catalyzing chemical reactions within the body.

Catalytic Action of Enzymes

• Firstly, enzymes facilitate the retention of substrates for chemical reactions by providing active sites that securely hold the substrate molecules in optimal positions. This ensures efficient interaction between the substrate and reagents. Drugs and substrates often compete for occupancy in daily life at these active sites.
• Secondly, enzymes contribute functional groups for attacking substrates and executing chemical reactions.

Drug-Enzyme Interaction:

Drugs can inhibit enzyme activities by blocking their binding sites, preventing substrate binding or obstructing catalytic activity. Enzyme inhibitors achieve this by competing with natural substrates for binding at the active site, known as competitive inhibition. Alternatively, some drugs bind to specific locations on enzymes called allosteric sites, inhibiting their activity by inducing conformational changes away from the active site.

Receptors as Drug Targets

Receptors, essential for cellular communication, are primarily embedded in the cell membrane, with parts extending both inside and outside. They interact with targeted drugs in their outer regions. Neuronal cells communicate via receptors, receiving chemical messengers secreted by other neurons. Due to differences in their binding site structures, receptors exhibit selectivity for specific chemical messengers. Antagonistic drugs inhibit natural receptor function, while agonists mimic it.

3.0Importance of Chemistry in Food

Chemistry plays a crucial role in food through various applications such as preservatives, food colours, flavours, sweeteners, and nutritional supplements.

4.0Cleansing Agents 

Cleansing agents eliminate dirt, dust, odours, stains, and other residues from surfaces. They work by reducing surface tension, enabling water to be cleaned effectively. Water alone is ineffective because surface tension inhibits cohesive forces. Soaps and detergents are common household chemicals employed for this purpose.

Soaps

Soaps, a traditional detergent, has been used for an extended cleaning period. They are composed of sodium or potassium salts derived from long-chain fatty acids such as stearic, oleic, and palmitic acids. Producing soaps involves heating fats (specifically glyceryl esters of fatty acids) with aqueous sodium hydroxide solutions, known as saponification.

During this reaction, esters of fatty acids undergo hydrolysis, resulting in the formation of soap, which remains in colloidal form.

Surfactants, also known as surface active agents, are critical components found in soaps. Their primary function is to reduce the surface tension of water, facilitating its ability to wet surfaces. Surfactants attach to water molecules at one end, allowing water to spread and adhere to surfaces. Meanwhile, at the other end, surfactants bind to oils and dirt. This dual action enables water to clean surfaces by loosening and removing contaminants effectively.

Synthetic Detergents

Synthetic detergents are cleansing agents that possess all the properties of soaps but do not contain soap. They can be effectively utilized in soft and hard water environments, producing foam even in hard water conditions. Additionally, certain detergents are capable of generating foam even in ice-cold water.

Synthetic detergents are mainly classified into three categories

• Anionic detergents
• Cationic detergents and 
• Non-ionic detergents

• Anionic detergents are sodium salts derived from sulfonated long-chain alcohols or hydrocarbons. They are formed by neutralizing alkyl hydrogen sulfates or alkyl benzene sulphonic acids with alkali. Anionic detergents are widely used in household chores and are also incorporated into toothpaste formulations.

• Cationic detergents consist of quaternary ammonium salts of amines paired with acetates, chlorides, or bromides as anions. The cationic component features a lengthy hydrocarbon chain and a positively charged nitrogen atom, earning them the designation "cationic detergents." Cetyltrimethylammonium bromide is a prominent example and is commonly employed in hair conditioners. Due to their germicidal properties and higher cost, cationic detergents are utilized more sparingly.   

• Non-ionic detergents lack any ions in their composition. They are typically formed through the reaction of stearic acid with polyethylene glycol. Liquid dishwashing detergents are a typical example of non-ionic detergents. Their cleansing mechanism mirrors that of soaps, as they remove grease and oil through micelle formation.