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MARA JUNIOR SCIENCE
COLLEGE TAIPING,PERAK
FOLIO CHEMISTRY FORM 5:
CHEMICAL FOR CONSUMER
NAME :MUHAMMAD ABDUL AZIZ B.MAT YUSOF
CLASS :404/504
COLLEGE NO.:10167
I/C :940630-03-5241
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Soap and Detergents
Soap1. Cleansing agents are chemical substance used to remove grease and dirt.
2. There are two type of cleansing agents :
a) Soaps
b) Detergents
3. Soaps are sodium or potassium salt of fatty acids that contains 12 to 18
carbon atoms per molecule.
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4. Soaps are cleansing agents made from animal fats or vegetable oil by
saponification.
The History of Soap Manufacturing
1. Soap have been used for more than 3000 years. It was recorded that theBabylonians were making soaps around 2800 B.C.
2. The Purifying Oils were recorded on Hebrew tablets in 4000 B.C.
3. In ancients time, soap made from ashes of plants which contain sodium
carbonate and potassium carbonate. The ashes were boiled with lime
(calcium oxide) to produce caustic potash (potassium hydroxide). Caustic
potash is then boiled with the animal fats to produce soap.
a) Ash + Lime boiled Caustic Potash
(K2CO3) (CaO) (KOH)
b) Caustic Potash + Animal Fats boiled Soap
4. In 1861, the Belgian Chemist Ernest Solvay (1838-1922) discovered the
process to make soda (sodium carbonate) from common salt (sodium
chloride) and calcium carbonate.
5. This process is known as the Solvay Process which produces sodium
carbonate cheaply for industrial use. Sodium carbonate (often called soda or
soda ash) is used for making glass, soaps and detergents.
6. Michel Chevreul (1786-1889), a French chemist, was noted for his research in
the composition of animal fats are composed of fatty acids and glycerol. This
discovery contributed to the rapid development of the soap and candle
industry.
Preparation of soap by saponification
1. Soap is a cleansing agents produced by the reaction between sodium
hydroxide or potassium hydroxide with animal fats or vegetable oils. This
reaction is known as saponification.
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2. Fats and vegetable oils are large, naturally occurring ester molecules. When
fats or oils are boiled with concentrated alkalis, such as sodium hydroxide,
saponification occur and the ester molecules are broken down into soap and
glycerol.
Fats or vegetable oils + concentrated alkalis soap +glycerol
3. Saponification is the alkaline hydrolysis of ester using alkali solutions. From
the chemist aspect, soaps are sodium salts or potassium salts of long chain
carboxylic acids (with 12 to 18 carbon atoms per molecule).
4. Some examples of soaps are shown below.
a) Sodium palmitate, C15H31COONa
b) Sodium oleate, C17H33COONa
c) Sodium stearate, C17H35COONa
Additives such as perfume, colouring matter and sometimes antiseptics are
added to soaps to enhance their marketability .
5. Glyceryl tristearates are naturally occurring esters commonly found in animal
fats and vegetable oils. When the ester is boiled with concentrated sodium
hydroxide solution, saponification (alkaline hydrolysis) occurs and mixture of
sodium stearate (soap) and glycerol is obtained.
CH2COOC17H35 CH2OH
CHCOOC17H35 + 3NaOH CHOH
(heating)
CH2COOC17H35 3C17H35COONa +CH2OH
Glyceryl tristearate Sodium stearate (soap)Glycerol
6. The soap produced can be precipitated by adding common salt (sodium
chloride) to the reaction mixture.
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7. The sodium chloride added reduced the solubility of soap in water. As a
result, precipitation of soap occurs.
8. The properties of soap depend on :
a) The type of alkali used for saponification
b) The type of animal fats or vegetable oils used.
9. Soaps produced from sodium hydroxide are hard, whereas soaps produced
from potassium hydroxide are soft.
10.Animal fats (tallow) from cows and vegetable oils (such as palm oil or olive
oil) ae used for making soap.
The structure of soap molecule
1. When soap is dissolved in water, it will dissociate and produce sodium ions
and carboxylate ions (RCOO-). For example, sodium stearate dissolves in
water to form sodium ions and stearate ions.
C17H35COONa (s) + water C17H35COO- (aq)
sodium stearate stearate ions
+ Na + (aq)
2. The active substance in soap is the carboxylate ion, for example, stearate
ion. The stearate ion consist of two parts : the head and the tail. The
head id negatively charged and the tail is a long hydrocarbon chain.
3. The head contains the -C-O- ions which dissolves readily in water
(hydrophilic) but does not dissolve in oil. Conversely, the tail contains a long
hydrocarbon chain which is insoluble in water (hydrophobic) but dissolves
readily in oil.
4. Soaps made from palmitic acid are known as sodium palmitate. Figure 5.2
shows the structure of the palmitate ion in soaps.
5. The figure 5.3 9a) shows the molecular model of palmitate ion and Figure 5.3
(b) shows the simple representation of the structure of the palmitate ion.
O
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(pg 548)
(a) The molecular model of the palmitate ion.
(b) The diagrammatic representation of the soap ion.
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Detergents1. Detergents are synthetic cleansing agents made from hydrocarbons obtained
from petroleum fractions. Thus, detergents are petrochemicals.
2. Detergents can be classified into three main types, depending on the charge
on the detergent ion.
a) Anionic detergents where the head of the detergent particle contains a
negatively charged ion.
Example : R O SO3-Na+ (Sodium alkyl sulphate)
b) Cationic detergents where the head of the detergent particle contains
a positively charged ion.
Example : R N (CH3)3+BR-
c) Non ionic detergents
Example : R O CH2CH2OH
3. There are two types of anionic detergents :
a) Detergent molecule with a benzene ring such as sodium alkylbenzene
sulphonate.
Where R represents a
long hydrocarbon chain.
Positively
charged
ion
Negatively
charged
ion
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We can represent the detergent ion, alkylbenzene sulphonate ion, more
simply as :
b) Detergent molecule without a benzene ring such as sodium alkyl
sulphate.
We can represent the detergent ion, alkyl sulphate ion as :
R OSO3-
Preparation of detergents
1. The detergent, sodium alkyl sulphate can be prepared from alcohols with
chain lengths of 12 to 18 carbon atoms in two steps.
Steps 1: Reaction with concentrated sulphuric acid
Step 2 : Neutralisation with sodium hydroxide solution.
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2. An example of a long chain alcohol is didecan 1 ol, CH3(CH2)10CH2OH. The
detergent prepared from dodecan -1 ol is called sodium dodecyl sulphate
(IUPAC name) or sodium lauryl sulphate (common name). CH3(CH2)10CH2O-
SO3-Na+ .
3. Sodikum alkylbenzene sulphinates, were first used in 1940s. It can be
prepared in three steps. The starting materials for making this detergents ina long chain alkene, RCH = CH2 , obtained from the cracking of petroleum.
a) Step 1 : Alkylation
Alkylation is the introduction of the alkyl group to an organic molecule.
b) Step 2 : Sulphonation
Alkylbenzene produced the react with concentrated sulphuric acid acid
to form alkylbenzene sulphonic acid.
Sulphonation is the introduction of the sulphonic acid group, -SO3H to
an organic molecule to form sulphonic acid.
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c) Step 3 : Neutralisation
Alkylbenzene sulphonic acid produced is the reacted with sodium
hydroxide to form sodium alkylbenzenesulphonate, the detergent
The structure of detergent molecule
When a detergent is dissolved in water, it dissociates to form sodium ions (Na+)
and detergent ions. The detergent ions have the same basic structure as the soap
ions, that is consist of two parts :
a) The head is the sulphate group (-OSO3-), which is negatively charged
and hydrophilic (dissolves readily in water but not in oils and grease).
b) The tail is the long hydrocarbon chain, which is neutral and
hydrophobic (dissolves readily in oils and grease, but not in water).
alkyl sulphate ion
Alkylbenzene sulphonate ion
The cleansing of soap and detergent
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1. The cleansing action of soap or detergent depends on their chemical bonding
and structures.
a) The ionic head (negatively charged) is soluble in water (hydrophilic)
but insoluble in oily layer.
b) The long hydrocarbon tail (neutral) is insoluble in water (hydrophobic)
but soluble in oily layer.
2. Oil cannot be washed away from clothing with water because oil (a covalent
molecult0 is insoluble in water.
3. Lifting greasy dirt from the surface cloth. When soap or detergent is added to
the dirty surface of a piece of cloth covered with a layer of oil or grease.
a) The negatively charged head (hydrophilic) of soap ions or detergent
ions dissolves in water.
b) The hydrocarbon tail (hydrophobic) of soap or detergent ions
dissolves in the layer of grease.
4. I the water is agitated slightly, the grease begins to be lifted off the surface.
This cause by the forces of attraction between the water molecules and the
negatively charged heads.
The cleansing action of soap
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5. On further agitation during washing, the greasy dirt is lifted from the surface.
6. Emulsifying dirt in water
a) Soaps and detergents can act as emulsifying agents to emulsify oils
and grease.
b) The process of emulsification breaks large drops of grease into smaller
droplets that floats in water. The greasy droplets repel on another
because they carry the same charge. As a result, the grease is
suspended in the solution.
c) When the cloth is rinsed with the water, the droplet will be carried
away.
d) The cleaning process become more efficient in the water containing
the soap or detergent solution is stirred
Additives in detergents
1. Modern detergents used for washing clothes usually contains a few types of
additives to :
a) Increase their cleaning power.
b) Make them attractive and saleable.
2. Only about 20% of the substances in a detergent are cle4ansing agents
(sodium alkyl sulphate or sodium alkylbenzene sulphonate). The other
substances are additives. The examples of addictives and their functions are
described as follows :
3. Builders : Sodium tripolyphosphate (Na5P3O10)
a) Sodium tripolyphospathe is usd to soften hard water. In the presence
of sodium tripolyphosphate, Ca2+ ions and Mg2+ ions are removed.
b) Sodium tripolyphosphate increases the pH value of water. In this way,
muddy dirt can be removed.
4. Whitening / bleaching agents : sodium perborate
a) Bleaches (bleaching agents) remove coloured stains by oxidation
process. When coloured stanis are oxidized, the colour will disappear.
b) The whitening (bleaching) agents commonly used in detergent is
sodium perborate (NaH2BO43H2O). Sodium perborate decomposes in
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hot water to release oxygen (an oxidising agents) which is responsible
for the whitening (bleaching) action.
c) Unlike chlorine, oxygen does not bleach the colour of dyes are not
damaging to fabrics. When properly used, the perborate bleaches
make fabrics whiter than chlorine bleaches and the colourful dyes of
the fabrics do not fade when dirty stains are removed.
d) Besides sodium perborate, sodium hypochlorite, (NaCIO) can also be
used as bleaches in detergents. The IUPAC name of sodium
hypochlorite is sodium chlorate (I).
e) Sodium hypochlorite releases chlorine that bleaches with dirty stains.
However, high concentrations of chlorine can be quite damaging to
fabrics. These bleaches do not work well on synthetic fabrics (polyster
fabrics), often causing a yellowing rather than the desire whitening.
Also chlorine causes the dyes on fabrics to fade.
5. Biological enzymes : Amylase, lipase, and protease
a) Protein stains such blood, milk, and tomato sauce cannot be removed
by the ordinary detergents because these types of stains are insoluble
in water.
b) Biological enzymes in detergents can break down fat and protein
molecules in food stains. The fatty acids, glycerol and amino acids
produced are soluble in water and are removed during washing.
6. Brighteners
a) Figure below shows the action of brighteners. The brighteners absorb
the invisible ultra-violet and re-radiate it as blue light.
Brightener
Cloth
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b) Brighteners make fabrics appear whiter and brighter because the blue
light can hide any yellowing on the fabrics. Blue light added to the
yellow light reflected on old fabrics make them look white.
7. Drying agents ; Sodium sulphate and sodium silicate
Anhydrous sodium sulphate and sodium silicate (Na2S2O3) are used as drying
agents to ensure that the detergent in powdered firm is always in a dry
condition.
8. Stabilisers
a) The functions of stabilizers is to prevents the formation of foam.
b) In an automatic washing machine, excessive foam can stop the pump
working. So, washing powders for automatic washing machine are
made using detergents that are good at removing and emulsifying
grease, but do not produced foam.
9. Perfumes
Perfumes are added to make clothes smell fresh and clean.
The effectiveness of soaps and detergents as cleansing agents
Advantages of soaps
1. Soaps are effective cleansing agents in soft water, that is water does not
contain Mg
2+
and Ca
2+
ions.
2. Soaps do not cause pollution problems to the environment. This is because
soaps are made from chemical found in animals and plants. This means that
soaps are biodegradable, that is they can be composed by the action of
bacteria.
Disadvantages of soaps
1. Soaps are ineffective in hard water, that is, water that contains magnesium
and calcium salts.
2. In hard water, soaps will react with Mg2+
and thus, soaps do not lather in hardwater.
3. Scum is grey solid that is insoluble in water. It consists of magnesium
stearate and calcium stearate.
4. Soaps are not also effective in acidic water, for example rainwater containing
dissolves acids. H+ ions from acids will react with soap ions to produce
carboxylic acids molecular size that are insoluble in water.
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5. Stearic acids and other carboxylic acids do not act as cleansing agents
because they exist mainly as molecules and do not anionic hydrophilic ends
(head) that dissolves in water.
Advantages of detergents
1. Detergents are cleansing agents that are effective in soft water as well as
hard water. This is because detergents do not form scum with Mg+ and Ca2+
ions found in hard water.
2. The detergents ions (R O SO3- and R SO3
- )react with Mg+ and Ca2+ ions in
hard water. However, the magnesium salts and calcium salts which are
formed are soluble in water. Hence, the scum is not formed and the
detergents are still active in hard water and lathers easily.
3. Detergents are synthetic cleansing agents. This means that the structure of
the hydrocarbon chain can be modified to produce detergents with specific
properties. Nowadays, different types of detergents have been synthesised
for specific uses such as shampoos and dish cleaner.
4. Furthermore, detergents are also effective in acidic water because H+ ion is
acidic water do not combined with detergents ions.
Disadvantages of detergents
1. Most detergents have branched hydrocarbon chains and are non-
biodegradable, that is, they cannot decomposed by bacteria. As a result, non-
biodegradable detergents cause water pollution.
2. Phosphates in detergents act as fertilizers and promotes the growth of water
plants and algae. When the plants die and decay, they will used up the
oxygen dissolves in water. This will decrease the oxygen content in water and
kill fishes and other aquatic lives.
3. Detergents produce a lot of foam in water. The layer of foam that covers the
water surface will prevents oxygen from dissolving in water. This condition
will cause fish and other aquatic life ti die from oxygen starvation.
4. Additives such as sodium hydrochlorite (bleaching agents) releases chlorine
gas in water that is acidic. Chlorine gas is highly toxic and kills aquatic life.
Uses of food additivesTypes of additives and examples
1. Food preservative have been used since ancient times. Ancient civilization
used salt to preserve meat and fish, herbs and spices to improve the flavor of
food.
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2. Food additives are chemicals that are added to food in small quantities for
specific purposes such as protection against bacterial attack or restoring the
colour of food destroyed during food processing.
3. Food additives are used :
a) To retard food spoilage and to preserve food (longer shelf life).
b) To make food taste better or smell better.
c) To add colouring to food so that the food looks fresher, more
interesting or more appealing.
4. There are two main groups of food additives :
a) Preservatives and antioxidants to protect food from being spoiled by
bacterial attact or atmospheric oxidation. In this way, the food can be
kept longer.
b) Flavouring agents, stabilizers, thickening agents (thickeners), and dyes
(colouring agents) to enhance the taste, smell and appearance of the
food.
5. Table below show a list of different types of food additives, their functions
and examples of each types.
Type of foodadditive Examples of food additive
Preservatives Sodium nitrite ; sodium nitrate ; benzoic acid ; sodiumbenzoate ; sulphur dioxide ; sodium sulphite ; sorbic acid; sodium sorbate
Antioxidants Ascorbic acid (vitamin C) ; BHA (butylatedhydroxyanisole) ; BHT (butylated hydrixitoluene) ; citricacid ; sodim citrate
Flavouring agents Monosodium glutamate (MSG) ; aspartameStabilisers andthickening agents
Gelatin ; acacia gum (agar)
Dyes (colouring
agents)
Azo compounds ; tripheny compounds
Functions of food additives
Preservatives
1. Preservatives are chemicals that are added to food to retard or to prevent the
growth of microorganism such as bacteria, mould or fungus, so that the food
can be stored for a long time.
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2. In ancient times, food additives from natural sources such as salt, sugar and
vinegar were used to preserve food and to make the food taste better.
3. Nowadays, synthetic preservatives are used, table below shows the types of
preservatives commonly used. Many of the preservatives are organic acids
and salts of organic acids.
Preservative Molecular formula UsesSodium nitriteSodium nitrate
NaNO2NaNO3
To preserve meat, cheese and driedfish.
To prevent food poisoning in cannedfoods.
To maintain the natural colour of meatand to make them look fresh
Benzoic acidSodiumbenzoate
C6H5COOHC6H5COONa
To preserve sauce (olyster, tomato orchilli), fruit juice, jam and margarine
Sulphur dioxide
Sodium sulphite
SO2
Na2SO3
Used as bleaches and antioxidants to
prevent browning in fruit juices. Maintain the colour and freshness of
vegetables.
To prevents the growth of yeast
Antioxidants
1. Antioxidants are chemicals that are added to foods to prevent the oxidation
of fats and oils by oxygen in the air.
2. Foods containing fats or oils are oxidized and become rancid when exposed
to air.
3. When the fats and oils are oxidized, rancid product are formed. This makes
the food unpalatable. The rancid product are volatile organic compound with
foul odours (for example , butanoic acid, C3H7COOH).
4. Antioxidants are added to fats, oils, cakes, sausages, biscuits and fried foods
to slow down the oxidation process so that these foods do not become rancid.
Flavouring agents
1. There are two types of flavouring agents : artificial flavours and flavour
enhancer. They are added to foods to make them taste better.
2. Flavour enhancer have little or no taste of their own. They are chemicals that
are added to food to bring out the flavours or to enhance the taste of food.
3. An example of a flavour enhancer is monosodium glutamate (MSG). MSG is
used to enhance the flavours of other foods.
4. Artificial flavour includes sweeteners and other flavours such as peppermint or
vanilla. Aspartame and saccharin are examples of artificial sweeteners.
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5. Both aspartame and saccharin can be used as a substitute for sugar to
enhance the sweetness in food and drink. However, the used of saccharin is
banned in many countries because it is carcinogenic. Aspartame has largely
replaced saccharin as the artificial sweetener or choice.
6. Many esters have fruity odours and tastes and are used as artificial flavours.
Table below shows some examples of esters that are used in making drinks.
Ester Benzylethanoate
Octylethanoate
Ethylbutanoate
Flavour Strawberry Orange Pineapple
Stabilisers and thickening agents
1. Stabilisers and thickening agents improve the texture and the blending of
foods.
2. Stabilisers are chemicals that are used to enable oil and water in the food tomix together properly in order to form an emulsion of oil and water. Examples
of stabilizers are gelatin and acacia gum.
3. Stabilisers are added to improve the texture of foods. For examples,
stabilisers are added to ice-cream and peanut butter to keep them smooth
and creamy.
4. In the presence of stabilisers, the emulsion of oil does not separate from
water. This means that the stabilisers improves the stability of some foods
such as ice-cream and salad dressings (mayonnaise).
5. Without stabilisers, ice crystals would form in ice-cream, particles of
chocolate would settle out of chocolate milk, oil and vinegar in salad dressing
will separate as soon as mixing is stopped.
6. Thickening agents are chemicals that are added to foods to thicken the liquid
and to prevent the foods from becoming liquid. Thickening agents (also called
thickeners) absorb water and thicken the liquid in foods to produce a jelly-like
structure.
7. Most thickening agents are natural carbohydrates. Gelatin and pectin are
added to help jams and jellies to set.
Dyes
1. Dyes (colouring agents) are chemicals that are added to foods to give them
colour so as to improve their appearance.
2. Some foods are naturally coloured, but the colour is lost during food
processing. The foods industry uses synthetic food colours to :
a) Restore the colour of food lost during food processing.
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b) Enhance natural colours, so as to increase the attractiveness of foods.
c) Give colour to foods that do not have colour.
3. Some dyes are naturally plant pigments while others are synthetically
prepared. The synthetic colours used in foods are azo and triphenyl
compounds. Both these compounds are organic compounds.
4. The synthetic dyes , brilliant blue, is an example of triphenyl compound. The
synthetic dye, tartrazine and sunset yellow are examples of azo compounds.
5. Azo compounds are organic compounds containing the diazo group, - N = N -,
and are usually yellow , red, brown, black in colour. Triphenyl compounds are
organic compounds containing three phenyl groups, -C6H5, and are usually
green. Blue or purple in colour.
Effect of food additives on health
1.The types of food additives allowed and the quantity permitted are controlled
by the 1983 Food Act and the 1985 Food Regulation.
2. The permissible quantity depends on the type of food and the food additives.
For example, benzoic acid added must not exceed 800 mg per kg in cordial
drinks, whereas sodium nitrite must not exceed 100 mg per kg in meat
product.
3. The excessive intake of food additives for a prolonged period of time will ruin
our health. The side effects arising from taking food additives are allergy,
cancer, brain damage and hyperactivity.
4. Allergy
a) Food additives such as sodium sulphite (preservative), BHA and BHT
(antioxidants), MSG (flavouring) and some food colours (e.g, Yellow
No. 5) can cause allergic reactions in some people.
b) The symptoms of MSG allergy are giddiness, chest pain and difficulty in
breathing. This condition is called the Chinese restaurant syndrome
c) The presence of sodium nitrate or sodium nitrite in food can cause
blue baby syndrome that is fatal for babies. This syndrome is due to
the lack of oxygen in the blood. Hence, the use of nitrate and nitrite isallowed in baby foods.
5. Cancer
a) Chemicals that cause cancer are called carcinogens. Sodium nitrite (a
preservative) is a potent carcinogen.
b) The nitrite react with the amines in food to produce nitrosamine which
can cause cancer.
6. Brain damage
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Excessive intake of nitrites for a prolonged periodof time can cause brain
damage. In this condition, the supply of oxygen to the brain is disrupted and
this cause brain damage.
7. Hyperactivity
a) Food additives such as tartrazine can cause hyperactivity.
b) Children who are hyperactivity become very active, find it difficult to
relax or sleep and are very restless.
The rationale for using food additives
Advantages
1. To prevent food spoilage
a) Oxidation and microorganism (bacteria, fungi) are the main causes inthe decomposition of food. In hot climate, meat and fish rot easily. The
use of preservatives is an effective way to prevent food spoilage and to
ensure that foods can be supplied throughout the year.
b) If preservative are not used, food spoilage might drastically reduce the
food supply, making foods to cost more.
c) Few deaths are associates with the use of food additives. However,
many people die due to food poisoning caused by bacterial toxins.
2. To improve nutritional value
During food processing, vitamins and minerals may be destroyed. Thus,
additives that improve nutrition can be added. These additives include
vitamin B, C and D, and minerals such as iron. The addition of these additives
increase the nutritional value of foods.
3. For medical reasons
a) Aspartame and sorbitol are used to make foods and drinks sweet
without using sugar. These food additives are particularly useful as
artificial sweeteners for diabetic patients.
b) Artificial sweeteners give the sweet taste but without adding calories
to the food. Thus, they can be used to reduce obesity.
c) Potassium iodide is added to table salt to reduce the incidence of
goitre.
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d) Vitamin C is added to friut juices to prevent scurvy. Vitamin D is added
to margarine to prevent rickets.
Disadvantage
1. Eating food additives such as preservatives, antioxidants and flavourenhancers is excess quantities over a long period of time is detrimental to
health.
2. Some food additives are used to make foods look more appealing. These
additives have little nutritional value. Eating such foods increases the risk of
health hazard.
3. Some foods are fortified with excess amounts of nutrients, such as vitamins
A and D, or of trace elements, such as copper and zinc. Eating foods with
excessive amounts of nutrients can ruin our health.
MedicinesSources and uses of traditional medicines
1. A medicine is a substance used to prevent or cure diseases or to reduce pain
and suffering due to illnesses.
2. Traditional medicines are medicines derived from natural sources such asplants and animals without being processed chemically.
3. Since ancients, mankind had used various types of plants and roots, animals
and animal part to cure diseases.
4. Medicines obtained from plants are known as herbal medicines. The sources
and uses of some herbal medicines are shown in table below :
Plant Part of the plantused
Uses
Garlic Corm For preventing flu attack For reducing high bloodpressure
Ginger Rhizome(horizontalunderground stem)and leaves
For treating stomach pain dueto wind in the stomach
For supplying heat energy tokeep the body warm
For preventing flu attackAloe vera Leaves For preventing itchy skin
For treating burns (scalding)on the skin
Lemon (lime) Fruits For treating boils or abscesses
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on the skin
For preventing flu attack
For treating skin diseasesQuinine Bark of Chinchona
tree For treating malaria
For preventing muscle cramps
Ginseng Roots As a tonic to improve the
overall health of humanbeings
For increasing energy,endurance and reducingfatigue
Lemon grass Stem/leaves Has antibacterial andantifungal properties
For treating coughTongkat Ali Roots As a tonic for after a birth and
general health
Modern medicines
1. Before the 20th century, most medicines were extracted from plants (herbal
medicines). Since 1900. Thousands of modern drugs have been synthesised
from organic compound.
2. Modern medicines can be classified as follows based on their effects on the
human body.
3. Some examples of modern medicines are analgesics, antibiotics,
psychotherapeutic drugs.
4. Modern drugs have a trade name and a generic name. For example, the
analgesic aspirin (generic name) is sold under different brand names such as
Caprin and Disprin. Similarly, paracetamol (generic name) is sold under the
trade name of Panadol.
5. Modern medicines usually contain a mixture of active ingredients prepared in
different forms, such as capsules, pills, solutions or suspensions. For
example, Alka-Seltzer (used as an antacid) contains sodium bicarbonate
(NaHCO3), citric acid and aspirin. It is the sodium bicarbonate then neutralizes
the excess stomach acid.
Fucntion of each type of modern drug
Analgesics
1. Analgesics are medicines that relieve pain. Examples of analgesics are
aspirin, paraccetamol, and codeine. Analgesics are sometimes called
painkillers.
2. Aspirin and paracetamol are mild painkillers whereas codeine is powerful
painkillers.
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3. Analgesics relive pain but do not cure the disease.
4. Aspirin : pain relief and anti-inflammatory action
a) The IUPAC name of aspirin is acetyl aslicylec acid. Aspirin contains two
functional groups, a carboxylic acid group and the ester group. Thus,
aspirin is aicidc in nature.
b) Uses of aspirin
Aspirin reduces fever and inflammable as well as relives pain. Aspirin
is used to :
(i) Reduce fever
(ii) Relieve headaches, muscle aches and joint aches
(iii) Treat arthritis, a disease caused by inflammation of the joints
(iv) Act as an anticoagulant. It prevents the clotting of blood andreduce the risk of the heart attack and strokes.
5. Paracetamol
a) Paracetamol have the following structural formula. Thus, unlike
aspirin, paracetamol is neutral in nature.
Pic pg 561
b) Paracetamol is similar to aspirin in its effects (that is, reduces fever
and relieves pain) but it does not reduce inflammation.
c) Paracetamol also reduces or relieves flu symptoms such as fever, bone
aches and runny nose.
6. Codeine
a) Codeine is an organic compound that contains the elements of carbon,hydrogen, oxygen and nitrogen.
b) Codeine is an analgesics and is used to relive mirror to moderate pain.
Codeine is more powerful than morphine. Codeine and morphine are
narcotic drugs
c) Codeine is also used in cough mixtures for suppressing coughs.
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Antibiotics : antibacterial medicine
1. Antibiotics are chemicals that destroy or prevent the growth of infectious
microorganism.
2. Two examples of antibiotics are penicillin and streptomycin.
3. Antibiotics are used to treat diseases caused by bacteria.
4. Antibiotics are not effective against diseases caused by viral infections such
as influenza, measles, or small pox.
5. Penicillin
a) Penicillin is derived from the mould Penicillium notatum.
b) Penicillin are used to treat diseases, caused by bacteria, such as
pneumonia, gonorrhea and syphilis.
c) Penicillin is only effective on certain bacteria. For example, it cannotbe used to treat tuberculosis.
6. Streptomycin is the antibiotic that is effective in treating tuberculosis.
Psychotherapeutic medicines
1. Psychotherapeutic medicines are a group of drugs for treating mental or
emotional illnesses.
2. Psychotherapeutic drugs can be divided into a few groups as shown in table
below :
Types of psychotherapeuticdrugs
Example
a) Stimulants Caffeine, amphetamineb) Antidepressant Prozacc) Antipsychotic
agentsChloropromazin
3. Stimulants
a) Stimulants are naturally occurring or synthetic drugs that stimulate
(excite) the activity of the brain and central nervous system.
b) Adrenaline is a stimulant that the body produces when it needs to
prepare for demanding or energetic activities.
c) Stimulants make a person more alert, more energetic, less tired and
more cheerful.
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d) Examples of stimulants are caffeine and amphetamines. Caffeine is a
week, naturally occurring stimulant and is found on coffee, tea and Cola
drinks.
e) Amphetamines are strong synthetic stimulants and increase alertness
and physical ability.
f) Amphetamines increase the heart and respiration rates, as well as the
blood pressure. As a result, it causes the body to postpone the need of
sleep and can reverse, partially and temporarily, the symptoms of
fatigue.
4. Antidepressants
a) Depression is a chronic illness. Most cases of depression are caused by
a chemical imbalance in the brain.
b) People experiencing depression feel hopeless. They experience a loss of
interest in everyday activities such as work or hobbies.
c) There is a strong correlation between the amounts of special chemicals(called neurotransmitters) in the brain and a persons mood. If these
chemicals get too low, the person may feel depressed.
d) Antidepressants are medicines that increase the brains level of
neurotransmitters, thus improving mood.
e) Antidepressants make a person feel calm and sleepy.
5. Antipsychotic medicines
a) Psychosis is the serious mental illness in which people lose touch with
reality. People with psychosis may,
Hear voice and see things that are not really there (hallucinations)
Have belief that are not based on reality (delusions)
b) In psychiatry, there are a number of disorders that are classified under
psuchosis, such as schizophrenias (madness), psychotic depression,
mania and so on.
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c) Psychotic patients have extreme mood swings. Their mood changes
rapidly from high spirit to deep depression.
d) Antipsychotic medicines do not cure symptoms to help the person live a
more normal life.
Side effects of traditional medicines
1. It is generally believed that traditional medicines have little side effects
compared to modern medicines. In fact, traditional medicines are sometimes
used to counteract the side effects of some modern medicines.
2. However, taking high doses of quinine for a prolonged period may cause
hearing loss. German health officials recently reported 40 cases of liver
damage which were linked to the herbal medicine containing kava-kava.
3. While the use of traditional medicine is rising globally, health experts have
insufficient data about how it affects patients.
4. The World Health Organisation( WHO) hopes to set up a global monitoring
system to monitor the adverse side effects of traditional medicines.
Side effects of modern medicines
Type ofmodern drug
Side effects
Aspirin Can cause bleeding in the stomach because aspirin is vey
acidic.
Can cause allergic reactions, skin rashes and asthmatic attacks
Amphetamines
People who abuse amphetamines are excitable and talkative.
Psychologically additive and can cause heart attack. Can cause anxiety, sleeplessness, aggressive behavior and
decrease appetite.
Can cause enlarged pupils, heavy perspiration and tremblinghands.
Codeine Can cause addiction.
Penicillin Can cause allergic reactions.
Can cause death for people who are allergic to it.
Streptomycin Can cause nausea, vomiting, dizziness, rashes and fever.
Can cause loss of hearing following long-term use.
Stimulants Can cause addiction.
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Antidepressants
Can cause addiction.
Can cause headaches, grogginess and loss of appetite.
Antipsychoticdrugs
Can cause dry mouth, blurred vision, urinary retention,constipation.
Can cause tremor and restlessness.
Sedation (make people calmer, or to make people sleepy)
Correct ways of using medicines
In taking any medicine, we should know why the medicine is prescribed, how the
medicine should be used, what special precautions should be followed, what special
diet should be followed, what are the side effects, and what storage conditions are
needed. In addition, we should note the following points :
1. Self-medication
Do not prescribe medicines for yourself (self-medication) or for other people.
Discuss with your doctor and listen to him concerning the medicine to betaken.
2. Follow the instructions given
Follow the instructions given by your doctor or pharmacist concerning the
dosage and method of taking the medicine.
3. Medicines for adult and children
Medicines for adult should not be given to children and vice versa.
4. Side effects
Visit the doctor immediately if there are symptoms of allergy or other effects
of the drugs.
5. Expiry date
Like foods, medicines also have expiry date. Do not take medicines after their
expiry dates.
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