chemistry in everyday life

1. Chemistry in
Everyday Life

2. Everyday Chemicals
Cleanliness:
Soaps, Detergents,
Bleaches, Toothpaste,
Nail Polish Remover
Clothes:
Synthetic Fibers,
Coloring Chemicals
Food Material:
Fertilizers, Pesticides,
Chemical Sweeteners.
Preservatives
Medicines,
Explosives,
Fuels,
Rocket Propellents,
And many more……

3. Classification of Drugs
Pharmacological Effect Drug Action Chemical Structure Molecular Targets
Classified on the basis of
the physiological effect
on our body
For example:
Anti-pyretic: used to reduce body
temperature
Anti-septic : used to kill or arrest
bacteria growth
Based on the action of a
drug on a particular
biochemical process
For example:
Anti-histamines: Inhibit the
action of the compound,
histamine which causes
inflammation in the body
Based on the chemical
structure of the drug.
Drugs classified in this
way share common
structural features and
often have similar
pharmacological activity
For example:
Sulphonamides: can suppress
multiplication of micro-
organisms. Therefore used as anti
bacterial
Drugs usually interact
with biomolecules such
as carbohydrates, lipids,
proteins and nucleic
acids.
These are called target
molecules or drug
targets.
Drugs possessing some
common structural
features may have the
same mechanism of
action on targets.

4. Drug Designing
Two Main considerations while designing a drug
Drug Target
Drugs interact with macro molecules such as
proteins, carbohydrates, lipids and nucleic acids
called targets
Correct choice of drug target is important to obtain
good therapeutic effect
Drug Metabolism
Drug travels through the body to reach its target
Should reach the target without getting metabolized
in between.
After its action, drug and its metabolites are excreted
without causing harm to the body

5. Enzyme as Drug Target
Catalytic action of enzymes:
In their catalytic activity, enzymes perform
two major functions:
Active sites of enzymes hold the substrate
molecule in a suitable position, so that it can
be attacked by the reagent effectively.
Substrates bind to the active site of the
enzyme through a variety of interactions
such as ionic bonding, hydrogen bonding,
van der Waals interaction or dipole-dipole
interaction
The second function is to provide functional
groups that will attack the substrate and
carry out chemical reaction.

6. Drug – Enzyme Interaction
Drugs can block the binding site of the
enzyme and prevent the binding of
substrate, or can inhibit the catalytic
activity of the enzyme. Such drugs are
called enzyme inhibitors
Non Specific Inhibition
Some drugs do not bind to the enzyme’s active
site. These bind to a different site of enzyme
which is called allosteric site. This binding of
inhibitor at allosteric site changes the shape of
the active site in such a way that substrate
cannot recognize it

7. Receptor as Drug Target
Receptors are proteins that recognize & respond to body’s own
chemical messengers such as hormones and neurotransmitters
Majority of these are embedded in cell membranes in such a way
that their small part possessing active site projects out of the
surface of the membrane.
There are a large number of different receptors in the body that
interact with different chemical messengers.
These receptors show selectivity for one chemical messenger over
the other because their binding sites have different shape, structure
and amino acid composition
Drugs that bind to the receptor site and inhibit its natural function
are called antagonists. These are useful when blocking of message
is required.
Drugs that mimic the natural messenger by switching on the
receptor, these are called agonists. These are useful when there is
lack of natural chemical messenger

8. Therapeutic action
of different classes
of drugs

9. Antacids:
Over production of acid in the stomach causes irritation and pain.
Until 1970, only treatment for acidity was administration of antacids, such as
NaHCO3 or a mixture of Al(OH)3 and Mg(OH)2.
Excessive hydrogencarbonate can make the stomach alkaline and trigger the
production of even more acid. Metal hydroxides are better alternatives
because of being insoluble, these do not increase the pH above neutrality.
Drug cimetidine (Tegamet), was designed to prevent the interaction of
histamine with the receptors present in the stomach wall. This
resulted in release of lesser amount of acid.
Importance of the drug was so much that it remained largest selling
drug in world until another drug, ranitidine (Zantac), was discovered.

10. Anti-histamines
Histamine is a potent vasodilator (group of medicines that
dilate (open) blood vessels). It has various functions. It
contracts the smooth muscles in the bronchi and gut and
relaxes other muscles, such as those in the walls of fine
blood vessels
Histamine is also responsible for the nasal congestion
associated with common cold and allergic response to pollen
Synthetic drugs, brompheniramine (Dimetapp) and
terfenadine (Seldane), act as anti-histamines. They interfere
with the natural action of histamine by competing with
histamine for binding sites of receptor where histamine
exerts its effect
Why do above mentioned anti-histamines not affect the secretion of acid in stomach?”
The reason is that antiallergic and antacid drugs work on different receptors
Histamine

11. Why do soaps not work in hard water?
• Hard water contains calcium and magnesium ions.
These ions form insoluble calcium and magnesium
soaps respectively when sodium or potassium soaps
are dissolved in hard water
• These insoluble soaps separate as scum in water and
are useless as cleansing agent
• In fact these are hindrance to good washing, because
the precipitate adheres onto the fiber of the cloth as
gummy mass
• Hair washed with hard water looks dull because of
this sticky precipitate
• Dye does not absorb evenly on cloth washed with
soap using hard water, because of this gummy mass