1 HAIR CARE Assoc. Prof. Dr.Pleumchitt Rojanapanthu Pharmacy Department, Faculty of Pharmacy Mahidol...
-
Upload
roy-richardson -
Category
Documents
-
view
220 -
download
2
Transcript of 1 HAIR CARE Assoc. Prof. Dr.Pleumchitt Rojanapanthu Pharmacy Department, Faculty of Pharmacy Mahidol...
11
HAIR CAREHAIR CAREHAIR CAREHAIR CARE
Assoc. Prof. Dr.Pleumchitt RojanapanthuAssoc. Prof. Dr.Pleumchitt Rojanapanthu
Pharmacy Department, Pharmacy Department,
Faculty of Pharmacy Mahidol University, Faculty of Pharmacy Mahidol University,
Bangkok, ThailandBangkok, Thailand
22
Women from all around the world choose hair styles to
their type of hair. Hair our personalities, whichever race we
come from
33
44
55
HairHairHairHair Getting to know hairGetting to know hair
Types of hairTypes of hair
Hair structureHair structure
Hair growth cycleHair growth cycle
66
Hair ColorHair Color
Physical properties of hairPhysical properties of hair
Chemical properties of hairChemical properties of hair
Hair (con.)Hair (con.)Hair (con.)Hair (con.)
77
ShampoosShampoos
ConditionersConditioners
“ “2 in 1” shampoos2 in 1” shampoos
Hair spraysHair sprays
Hair Care Hair Care ProductsProductsHair Care Hair Care ProductsProducts
88
Hair Care Hair Care Products (con.)Products (con.)Hair Care Hair Care Products (con.)Products (con.) Hair gelsHair gels Perming solutionsPerming solutions Hair dyesHair dyes etc.etc. General remarks about General remarks about
product developmentproduct development
99
Getting to Know HairGetting to Know HairGetting to Know HairGetting to Know Hair
All Land mammals (including) humansAll Land mammals (including) humans• have hairy skinshave hairy skins
Hair characteristics are inherited directly Hair characteristics are inherited directly
from our parents from our parents
• hair colorhair color
• hair typehair type
The same as your eyes & your skin The same as your eyes & your skin
1010
• Human are covered all over in hair except on Human are covered all over in hair except on
the palms of handsthe palms of hands
the sole of the feetthe sole of the feet
the lipsthe lips
• Hair is most obvious on the head and face Hair is most obvious on the head and face
including the nose and ears in some people including the nose and ears in some people
the armpits / the groin the armpits / the groin
the chest and legs (in men) the chest and legs (in men)
Hair distributionHair distribution
1111
• Average : 100,000-150,000 hair folliclesAverage : 100,000-150,000 hair follicles
Baby’s head : 1,100 follicles/mBaby’s head : 1,100 follicles/m22
Age 25 : ~ 600/mAge 25 : ~ 600/m22
Age 30-50 : ~ 250-300/mAge 30-50 : ~ 250-300/m22
• Each follicle grow about 20 new hairs in lifetimeEach follicle grow about 20 new hairs in lifetime
• Each new hair grows several year 1 meterEach new hair grows several year 1 meter
• Each hair falls out eventually and is replaced Each hair falls out eventually and is replaced
by a new hairby a new hair
HowHow much hair do we have much hair do we have
1212
• Different people have hair that differs in color, Different people have hair that differs in color,
length diameter, distributionlength diameter, distribution
• Influence factors :Influence factors :
Racial typeRacial type
AgeAge
Variation in human hairVariation in human hair
1313
Types of hairTypes of hair
3 types3 types
Lanuga hair Lanuga hair
• develops on an unborn baby develops on an unborn baby
• 3 3 months after the baby’s conceptionmonths after the baby’s conception
• fine and softfine and soft
• grows all over the body, at the same rategrows all over the body, at the same rate
• shed about 4 weeks before the baby is due to bornshed about 4 weeks before the baby is due to born
1414
Vellus hairsVellus hairs
• short hair, only 1 or 2 cm. Longshort hair, only 1 or 2 cm. Long
• contains little or no pigmentcontains little or no pigment
• follicle doesn’t have oil glandsfollicle doesn’t have oil glands
• never produce any kind of hairsnever produce any kind of hairs
1515
• long hairs that grow on the head, body arms long hairs that grow on the head, body arms
and legs and legs
• produced by follicles with produced by follicles with sebaceous glandssebaceous glands
• people inherited a tendency to baldness the people inherited a tendency to baldness the
• hair become thinner and shorter until look hair become thinner and shorter until look
like vellus hair like vellus hair
Terminal hairsTerminal hairs
1616
dd
Vellus hairs on a woman’s chin. These are normal when female
hormones decline, hairs on the chin can grow as strongly as
terminal hairs
1717
Variation with ageVariation with age
ChildhoodChildhood
Newly born full-term baby Newly born full-term baby
• Terminal hairs grow on the scalp &eyebrows
• All the rest of hair is vellus hair
• Baby grows the hair on the head grows
• Hair growth begin at the forehead then
extends to the back
1818
2-3 months old baby2-3 months old baby
- first hair may be shed naturally over an area- first hair may be shed naturally over an area
on the back of the headon the back of the head
- was thought to be head rubbing- was thought to be head rubbing
Hair broken by rubbingHair broken by rubbing
- - may found in other part of the headmay found in other part of the head
1919
Naturally occurring hair loss, which Naturally occurring hair loss, which
begins at age 8-12 weeksbegins at age 8-12 weeks
Mosaic patterns starting to develop; Mosaic patterns starting to develop;
the beginning of hair streams can also the beginning of hair streams can also
be seenbe seen
2020
• allall hairs on the head grow at the same rate hairs on the head grow at the same rate
• head carries an even covering of hairhead carries an even covering of hair
• individual hair begin to grow independentlyindividual hair begin to grow independently
• grow at different rate and different cyclesgrow at different rate and different cycles
First year babyFirst year baby
2121
•unruly hair which unruly hair which sticks straight upsticks straight up
•natural curlsnatural curls
•hair without pigmenthair without pigment
Features of children hairFeatures of children hair
2222
2323
Before puberty :Before puberty :
- - Scalp carries a mixture of short vellus-like hair Scalp carries a mixture of short vellus-like hair
and longer terminals hairs together with various and longer terminals hairs together with various
‘ ‘in between’ hair in between’ hair
At puberty :At puberty :
- Terminal hairs begin to appear in the- Terminal hairs begin to appear in the armpit,armpit,
groin & legs chin,groin & legs chin, chest & forearm chest & forearm
AdolescenceAdolescence
2424
• most of scalp hair are terminal hairs most of scalp hair are terminal hairs
• thicker in diameterthicker in diameter
After puberty :After puberty :
2525
• thethe hairs continue to grow strongly/hair hairs continue to grow strongly/hair
at 80 = at 50 at 80 = at 50
• the hairs get thinner as the age/at 80sthe hairs get thinner as the age/at 80s
only a few wisps remainonly a few wisps remain
Middle age and beyondMiddle age and beyond
2626
• a tiny cup-shaped pit burried deep in thea tiny cup-shaped pit burried deep in the
• fat of the scalpfat of the scalp
• follicle is the point from which the hair grows follicle is the point from which the hair grows
• well supplied with minute blood vessels well supplied with minute blood vessels
• temperature is normal body temperaturetemperature is normal body temperature
Hair StructureHair Structure
Hair follicleHair follicle
2727
• temperature is not affected by cold or hot watertemperature is not affected by cold or hot water
• the rate of growth depends on thethe rate of growth depends on the
amount of natural light : growing a little amount of natural light : growing a little
faster in winter when the days are shortfaster in winter when the days are short
Hair Structure (con.)Hair Structure (con.)
2828
Hair follicle Hair bulbHair follicle Hair bulb
Hair shaft Hair shaft
Hair bulbHair bulb
- lines in - lines in side the hair follicleside the hair follicle
- is a structure of actively growing cells- is a structure of actively growing cells
- produce a long fine cylinder of hair- produce a long fine cylinder of hair
-- new cells are continuously produced in the lower new cells are continuously produced in the lower
part of the bulbpart of the bulb
2929
(a) Longitudinal section of a hair within its follicle.(a) Longitudinal section of a hair within its follicle.
(b) Enlarged longitudinal section of a hair.(b) Enlarged longitudinal section of a hair.
3030
(c) Enlarged longitudinal view of the expanded hair bulb of (c) Enlarged longitudinal view of the expanded hair bulb of
the follicle which encloses the matrix, actively dividing epithelial the follicle which encloses the matrix, actively dividing epithelial
cells that produce the hair. cells that produce the hair.
3131
(d) Cross section of a hair and hair follicle.(d) Cross section of a hair and hair follicle.
3232
(e) Photomicrograph of scalp tissue showing numerous(e) Photomicrograph of scalp tissue showing numerous
hair follicles (24 hair follicles (24 XX).).
3333
Scanning electron micrograph showing a hair shaft emerging f rom a follicle at the epidermal surface. Not ice h ow th e s ca l
e like ce lls of th e cu t ic le ove rla p on e a n oth e r (1 5 0 0 x).
3434
• can be seen above the scalpcan be seen above the scalp
• consist mainly of dead cell Keratin consist mainly of dead cell Keratin
+ binding material + small amount of water + binding material + small amount of water
• terminal hairs are lubricated by natural oil (sebum) terminal hairs are lubricated by natural oil (sebum)
produced by sebaceous glands produced by sebaceous glands
• high level of hormones (androgens) high level of hormones (androgens) high level of high level of
sebumsebum
The Hair ShaftThe Hair Shaft
3535
• scales growing over the youngest partscales growing over the youngest part
(closet to the scalp) are smooth and unbroken (closet to the scalp) are smooth and unbroken
further along the hair have been damaged by further along the hair have been damaged by
cosmetic treatments and by mistreatment : (over-cosmetic treatments and by mistreatment : (over-
energetic brushing)energetic brushing)
Nature of cuticleNature of cuticle
3636
Nature of cuticle (con.)Nature of cuticle (con.)• little by little, they may break away :little by little, they may break away :
““weatheringweathering””
• healthy cuticle is more than just a protective layerhealthy cuticle is more than just a protective layer
• intact cuticle cells are smooth, glossy, and reflect light intact cuticle cells are smooth, glossy, and reflect light
from their surface (black hair reflects less light than from their surface (black hair reflects less light than
blond hair)blond hair)
3737
3838
The cuticle scale on a normal hair
(electronmicrograph)
3939
- Another normal hair but this came - Another normal hair but this came
from one of our nearest relatives from one of our nearest relatives
an oran or angutan! angutan!
A perfect hair seen under the A perfect hair seen under the
electron microscopeelectron microscope
4040
• keratin chains link by : disulphide bond and keratin chains link by : disulphide bond and
hydrogen bondshydrogen bonds
• disulphide bonds can be changed by chemical disulphide bonds can be changed by chemical
methods : perming and relaxing permanentmethods : perming and relaxing permanent
Hair shapeHair shape
4141
• hydrogen bonds can be easily broken aparthydrogen bonds can be easily broken apart
whenever the hair is wetted and form againwhenever the hair is wetted and form again
as it driesas it dries
• when they break the shape of hair changeswhen they break the shape of hair changes
• wet hair is wound on the roller, the dried hair wet hair is wound on the roller, the dried hair
keep the roller shape keep the roller shape temporarytemporary
Hair shape (con.)Hair shape (con.)
4242
• European around 70-90 micronEuropean around 70-90 micron
• Asian around 120 micronAsian around 120 micron
• People have average hair aroundPeople have average hair around
100,000 – 150,000 hairs100,000 – 150,000 hairs
Hair dimensionsHair dimensions
4343
• individual hair form inside a hair bulb deep individual hair form inside a hair bulb deep
in hair in hair
• follicle is tiny but powerful factoryfollicle is tiny but powerful factory
• each hair grows during many yearseach hair grows during many years
• shampooed, conditioned, cut, blown dry, exposal to shampooed, conditioned, cut, blown dry, exposal to
the sun and wind, colored, bleached, permed none of the sun and wind, colored, bleached, permed none of
these affected the these affected the hair growth hair growth
Hair growth cycleHair growth cycle
4444
• the hair spontaneously falls outthe hair spontaneously falls out
• the follicle rests for a little while andthe follicle rests for a little while and
starts to produce a new hairstarts to produce a new hair
Hair growth cycle Hair growth cycle
(con.)(con.)
4545
• anagen : the growing phase (anagen : the growing phase (~~1000 days)1000 days)
• catagen : the intermediate phase (catagen : the intermediate phase (~~10 days)10 days)
• telogen : the shedding phase (telogen : the shedding phase (~~100 days)100 days)
Stage of the hair cycleStage of the hair cycle
4646
• last between 3-7 years without interruptionlast between 3-7 years without interruption
• roughly 1 cm/month > 1 meterroughly 1 cm/month > 1 meter
• faster rate in winter than summerfaster rate in winter than summer
• melanin is made in hair bulb throughout melanin is made in hair bulb throughout
this phase this phase
Anagen (the growing phase)Anagen (the growing phase)
4747
• less pigment is made in older people,less pigment is made in older people,
hair cycle becomes shorterhair cycle becomes shorter
• follicles gradually give up producing long,follicles gradually give up producing long,
strong hair :strong hair :
• hairs become thinner and shorter thinning hairs become thinner and shorter thinning
of the hair degree of baldnessof the hair degree of baldness
Anagen (con.) Anagen (con.)
4848
• short resting phase : 2-4 weeksshort resting phase : 2-4 weeks
• no pigment is madeno pigment is made
• follicles stop producing hairfollicles stop producing hair
• the base of follicle moves upwardsthe base of follicle moves upwards
towards the surface of the skin towards the surface of the skin
Catagen (the intermediate phase)Catagen (the intermediate phase)
4949
• lastlast forfor - 34 - 34 monthsmonths
• new hair begin to grow from the hair folliclenew hair begin to grow from the hair follicle
• as it grow s upwards the old hair will be as it grow s upwards the old hair will be
shed naturally or easily be pulled outshed naturally or easily be pulled out
Telogen (the shedding phase)Telogen (the shedding phase)
5050
• at anytime around one in ten of the follicles at at anytime around one in ten of the follicles at
individual’s head is in the shedding phase individual’s head is in the shedding phase
• shedding is part of normal process of theshedding is part of normal process of the
replacement of old hair with new hairreplacement of old hair with new hair
• new hair emerges from the same openingnew hair emerges from the same opening
as the old oneas the old one
Telogen (con.)Telogen (con.)
5151
The hair follicle cycle The hair follicle cycle
5252
5353
Each of these long hairs has been growing for at least six years:
eventually it will fall out spontaneously; this growth and fall makes
up the hair cycle
5454
Naturally blond hair: this lady's anagen phase lasts Naturally blond hair: this lady's anagen phase lasts
for about four years for about four years
5555
Hair this long must have been growing for seven or eight years: just look at itsbeautiful condition
5656
This man is head of a religious cult whi This man is head of a religious cult whichch
requires its leader to be able to grow requires its leader to be able to grow his his hair long enough to reach the ground: hair long enough to reach the ground: his his
anagen period is probably around ten anagen period is probably around tenoror
twelve years. As he grows older and t twelve years. As he grows older and thehe
anagen period shortens, he may lose anagen period shortens, he may losehishis
jobjob
The golden hair of the impriso -ned fairy tale princess Rapunzel was long en ough to allow
her lover to climb it in order to reach her in - her tower a demonstration no t only of the
length of anagen in Rapunzel, but also of the inherent strength of hair
5757
A method of measuring the rate of hair growth: both cut A method of measuring the rate of hair growth: both cut
hairs and newly emerging hairs can be seenhairs and newly emerging hairs can be seen
5858
Electronmicrograph showing new hairs emerging from Electronmicrograph showing new hairs emerging from
the hair follicles of the scalp the hair follicles of the scalp
5959
• general health and general health and nutritional factorsnutritional factors
• starvationstarvation or crash diet loosing hair in 6-10 or crash diet loosing hair in 6-10
weeksweeks
• alcoholicalcoholic people have poor hair people have poor hair
• some some mineralsminerals may particularly important may particularly important
for hair growthfor hair growth
What controls hair growthWhat controls hair growth ? ?
6060
• lack of Znlack of Zn : produces only fine, sparse hairs : produces only fine, sparse hairs
even lost their hairseven lost their hairs
• Vit BVit B : known as panthenol, plays a: known as panthenol, plays a
part in hair growth, improvespart in hair growth, improves
physical propertiesphysical properties
(elasticity, strength and gloss)(elasticity, strength and gloss)
of the hair shaftof the hair shaft
Hair growth (con.)Hair growth (con.)
6161
• thyroid hormone speeds up growth in thyroid hormone speeds up growth in
resting hair folliclesresting hair follicles
• steroids taken by mouth slow down the growthsteroids taken by mouth slow down the growth
Hormones :Hormones :
6262
• Androgen : the most important factor regulating Androgen : the most important factor regulating
hair growth, thickness of hair shaft hair growth, thickness of hair shaft
: changes vellus - like hair : changes vellus - like hair
terminal hairterminal hair
• oestrogen : slow down hair growth duringoestrogen : slow down hair growth during
growth period, make the period longer growth period, make the period longer
Hormones (con.)Hormones (con.)
6363
This boy has a zinc deficiency, and his hair is very thin and sparse;
after treatment his hair is growing more strongly
6464
PigmentationPigmentationMelanin : Melanin : - produced by - produced by melanocytes at growing melanocytes at growing
phase (anagen)phase (anagen) - spread out throughout the - spread out throughout the
cortex, the more cortex, the more near near outer edge lie along the amino acid outer edge lie along the amino acid
chainschains - does not protect the - does not protect the
harmful effect fromharmful effect from sunlightsunlight - is found in 2 forms- is found in 2 forms
Hair ColorHair Color
6565
•Eumelanin : dark pigmented which Eumelanin : dark pigmented which
predominates in black predominates in black and and
brunette hair/oval brunette hair/oval shape shape
•Phaeomelain : lighter pigment, found Phaeomelain : lighter pigment, found in red in red
and blond hair/smaller, partly and blond hair/smaller, partly
oval and partly rod- shapeoval and partly rod- shape
Pigmentation (con.)Pigmentation (con.)
6666
6767
Melanin granules in the cortex of a hair
6868
• the arrangement of keratin bundlesthe arrangement of keratin bundles
the way the large bundles of keratin are the way the large bundles of keratin are
arranged within each hair shaftarranged within each hair shaft
• the position of hair bulb :the position of hair bulb :
African hair bulb may lie to the side of the African hair bulb may lie to the side of the
follicle, so the hair shaft grows out of the follicle at an acute anglefollicle, so the hair shaft grows out of the follicle at an acute angle
Factors affecting hair structure :Factors affecting hair structure :
6969
• irregular growth in the hair bulb :irregular growth in the hair bulb : if it varies if it varies
slightly to one side or the other, hair may grow wavyslightly to one side or the other, hair may grow wavy
• the shape of the follicle :the shape of the follicle : whether it is straight whether it is straight or or
curvedcurved
• the number of twists per unit length :the number of twists per unit length :
African hair has 12 times as many twist per cm.African hair has 12 times as many twist per cm.
as Caucasian hairas Caucasian hair
Factors affecting hair structure (con.) Factors affecting hair structure (con.)
7070
• StrengthStrength
• Elasticity Elasticity
• Static electricityStatic electricity
• Moisture contentMoisture content
• PorosityPorosity
• TextureTexture
Physical properties of hairPhysical properties of hair
7171
• a single hair can support a load of about 100 gma single hair can support a load of about 100 gm
• keratin protein of the cortex responsible for the keratin protein of the cortex responsible for the
• hair strength hair strength
• keratin is a protein chains contain high keratin is a protein chains contain high
concentration of an amino acid called “concentration of an amino acid called “cystinecystine””
• matrix contains high level of cystinematrix contains high level of cystine
Hair strengthHair strength
7272
• each cystine unit contains 2 cysteine amino acids in each cystine unit contains 2 cysteine amino acids in
different chain different chain
• the chains are linked by two sulphur atoms, the chains are linked by two sulphur atoms,
forming a very strong chemical bond forming a very strong chemical bond
““disulphide linkagedisulphide linkage””
• many disulphide bonds form down the length many disulphide bonds form down the length
of the keratin chainsof the keratin chains
Hair strength (con.)Hair strength (con.)
7373
Chemical bonds within the hair maintain its shape
7474
• one of the most important propertiesone of the most important properties
• can resist forces that could change itscan resist forces that could change its
shape, volume and lengthshape, volume and length
• lest spring back to its original lest spring back to its original
form without damageform without damage
• wet hair can increase the length up to 30% wet hair can increase the length up to 30%
and return to original length when it is driedand return to original length when it is dried
ElasticityElasticity
7575
• elasticity of hair depends on the longelasticity of hair depends on the long
keratin fibers in the cortexkeratin fibers in the cortex
• chemical treatment can alter the cortex chemical treatment can alter the cortex
and change the hair elasticityand change the hair elasticity
Elasticity (con.)Elasticity (con.)
7676
• poor elasticity :poor elasticity :
- stretch only to a limited extent- stretch only to a limited extent
- will break easily- will break easily
- cannot be permed satisfactorily - cannot be permed satisfactorily
• natural sunlight and artificial UV light natural sunlight and artificial UV light
damage chemicals of hair and its elasticitydamage chemicals of hair and its elasticity
Elasticity (con.)Elasticity (con.)
7777
Tensile and Elasticity of hair
7878
Static electricityStatic electricity
• rubbing drug hair / brushing / combingrubbing drug hair / brushing / combing
builds up static electric charge builds up static electric charge
• thethe charges tend to push each other apartcharges tend to push each other apart
• charged hair never lie smooth against charged hair never lie smooth against
each other each other “ fly away ” hair“ fly away ” hair
• stands out from the head stands out from the head
7979
8080
Moisture content :Moisture content :
Heat and humidityHeat and humidity• more moisturemore moisture
• less static electricity less static electricity
• collapsecollapse
Heat and drynessHeat and dryness• less moistureless moisture• more static electricitymore static electricity• more volumemore volume
8181
- wet hair swell cortex / lift cuticle - wet hair swell cortex / lift cuticle
scalesscales
- hair surface temporaly loses its smoothness- hair surface temporaly loses its smoothness
- wet hair - wet hair more friction matting more friction matting
and tangles (over vigorous shampoo)and tangles (over vigorous shampoo)
Moisture content (con.)Moisture content (con.)
8282
• cuticle covering cortex is intact : cuticle covering cortex is intact : almostalmost
water proof (very little water can go inwater proof (very little water can go in
and out)and out)
• shampoos do not damage the cuticle shampoos do not damage the cuticle
• treating the hair (permed or tinted)treating the hair (permed or tinted)
PorosityPorosityNormal hairNormal hair
8383
• temperature / applying an alkaline lotiontemperature / applying an alkaline lotion
separate the scaleseparate the scale
• allowing chemicals to go insideallowing chemicals to go inside
• after processing after processing scales close upscales close up
Porosity (con.)Porosity (con.)
8484
• processing many times / too much blow processing many times / too much blow
drying/ too high temperative / effect drying/ too high temperative / effect
of sun and wind of sun and wind
the scales lose the tightness the scales lose the tightness
the porous the porous
damage cuticle is fragiledamage cuticle is fragile
develop split end develop split end
Porosity (con.)Porosity (con.)
8585
the damage is worse as the time goes the damage is worse as the time goes
byby
the greater the damage, the more the the greater the damage, the more the
cortex swells with water cortex swells with water
the more water loses when it driesthe more water loses when it dries
repeated wetting and drying of therepeated wetting and drying of the
cortex, gradually weakens the hair cortex, gradually weakens the hair
Porosity (con.)Porosity (con.)
8686
• the larger the hair diameter the the larger the hair diameter the
coarser it will feel coarser it will feel
• different people’s hair naturally feel different people’s hair naturally feel
different soft / hard / silky / wirydifferent soft / hard / silky / wiry
• effected by degree of weathering of haireffected by degree of weathering of hair
TextureTexture
8787
Texture is affected by what has been put on it :Texture is affected by what has been put on it :
- spray : makes different feeling- spray : makes different feeling
- conditioner : feel soft and smooth- conditioner : feel soft and smooth
- - conditioner with silicone : protect theconditioner with silicone : protect the
hair cuticle hair cuticle
- damage to cuticle : alter the hair texture- damage to cuticle : alter the hair texture
Texture (con.)Texture (con.)
8888
Chemistry of HairChemistry of Hair
• Keratinization process in the follicle keratin + water soluble
substances : pentose, phenols, uric acid, glycogen, glutamic acid,
valine, leucine
8989
Chemistry of Hair (con.)Chemistry of Hair (con.)
• Keratin is composed of amino acidKeratin is composed of amino acid
• 18 out of 25 normal amino acids18 out of 25 normal amino acids are found in keratinare found in keratin
9090
• Organization of hair protein sets up by bonding in 3 ways :
Chemistry of Hair (con.)Chemistry of Hair (con.)
between parallel peptide chains
I Formation of H-bondsFormation of H-bonds
9191
between acidie and basic side chain
Chemistry of Hair (con.)Chemistry of Hair (con.)
II Formaton of salt linkage II Formaton of salt linkage
9292
Chemistry of Hair (con.)Chemistry of Hair (con.)
• amino acid contains two amino and two carlygl groups link together by a disulphide bond
III Formates of disulphide linkages III Formates of disulphide linkages
9393Structure for Structure for - keratin- keratin