jaiku
Well-Known Member
I came across this interesting info on keratin and ammino acids. I don't know if it has been posted yet. I got the info from www.keratin.com . There was alot of other info there too.
[FONT=Arial,Helvetica][SIZE=+1]What is hair fiber made of[/SIZE][/FONT]
The primary component of hair fiber is keratin. Keratins are proteins, long chains (polymers) of amino acids. Keratin proteins form the cytoskeleton (miniature skeleton within a cell) of all epidermal cells. Keratin filaments run within a cell from the inside of the outer membrane to weave a "basket" around the nucleus of the cell. Keratins are a principle part of the cells in the epidermis, hair, nails, feathers, hooves, horny tissues and the enamel of teeth.
Keratin accounts for 30% of the cellular protein of living epidermal cells and 85% of cellular protein of the dead cells in the stratum corunem (the scaly, dead or horny layer of the outer skin). In hair fiber, keratin proteins comprise 65-95% of the total hair fiber by weight. Each molecule of keratin is very small - about 10 nanometers across. To give you a sense of how small that is, 10,000 keratin molecules lined up side by side would cover the width of the average terminal scalp hair.
There are several subtypes of keratin proteins, some are called "soft" keratins and others are "hard" keratins. Basically, soft keratins are found in the skin and are relatively easy to break down whereas hard keratins are very resistant to degradation. Hard keratins do not dissolve in water and they are highly resistant to proteolytic enzymes. As you might have guessed, hair fiber is mostly made from hard keratin proteins.
Hair contains a high amount of sulfur because the amino acid cysteine is a key component of the keratin proteins in hair fiber. The sulfur in cysteine molecules in adjacent keratin proteins link together in disulfide chemical bonds. These disulfide bonds are very strong and very difficult to break apart. These disulfide chemical bonds linking the keratins together are the key factor in the durability and resistance of hair fiber to degradation under environmental stress. They are largely resistant to the action of acids but the disulfide bonds can be broken apart by alkali solutions. This property is exploited in perms and chemical hair straightening processes. Alkali is used to break the disulfide bonds in the keratins and make the hair weak. The hair is formed into a new shape and then acid is applied to neutralize the alkali and enable the disulfide bonds to reform. The reformed disulfide bonds hold the hair in its new shape.
Some cosmetics manufacturers claim to make hair products that contain keratin to strengthen hair or promote hair growth. However, the cells in hair follicles make all the keratin protein that they require from amino acids supplied via the blood. Eating keratin protein does not help hair growth. Eating hard keratins as found in hair fiber is pointless as they cannot be broken down and absorbed. The keratins simply pass straight through the gut. It would be much better to eat the constituent amino acids from which the hair follicle cells can make keratin. However, it is extremely rare in North America and Western Europe to have a deficiency in amino acids so severe that it affects hair fiber quality. Topically applying keratin to hair also has no long lasting effect. The keratins are mostly washed away in the shampooing process.
[FONT=Arial,Helvetica][SIZE=+1]What amino acids are present in hair fiber[/SIZE][/FONT]
Below is a table of the amino acids present in normal human hair in order of their quantity.
[FONT=Arial, Helvetica, sans-serif]Amino Acid[/FONT][FONT=Arial, Helvetica, sans-serif]Amount in residues extracted[/FONT]Cysteine17.5Serine11.7Glutamic acid11.1Threonine6.9Glycine6.5Leucine6.1Valine5.9Arginine5.6Aspartic acid5.0Alanine4.8Proline3.6Isoleucine2.7Tyrosine1.9Phenylalanine1.4Histidine0.8Methionine0.5
[FONT=Arial,Helvetica][SIZE=+1]What is the carbon, oxygen, hydrogen, nitrogen, and sulfur content of hair[/SIZE][/FONT]
In terms of raw elements, on average, hair is composed of 50.65% carbon, 20.85% oxygen, 17.14% nitrogen, 6.36% hydrogen, and 5.0% sulfur. Hair also contains trace amounts of magnesium, arsenic, iron, chromium and other metals and minerals.
[FONT=Arial,Helvetica][SIZE=+1]How many atoms are present in the average hair fiber diameter[/SIZE][/FONT]
The average scalp hair fiber diameter is between 80-120 micrometers. Hair fiber diameter varies depending on the location of the hair follicle, the ethnicity of the individual and the activity of hair diseases. An atom has a diameter 10 to the minus 10 meters. That's 0.0000000001m or 1 preceded by 9 zeros and a decimal point. So the diameter of the average hair fiber is ... er , umm, er ... (extensive counting of fingers and toes) ... 800,000 - 1,200,000 atoms. So the cross sectional area of a hair fiber asuming the cross section is circular (which is not always the case as curly hair as an oval cross section while straight hair has a circular cross section) contains 500,000,000,000 - 1,000,000,000,000 atoms. Remember the area of a circle is pi times the radius squared.
[FONT=Arial,Helvetica][SIZE=+1]What is hair fiber made of[/SIZE][/FONT]
The primary component of hair fiber is keratin. Keratins are proteins, long chains (polymers) of amino acids. Keratin proteins form the cytoskeleton (miniature skeleton within a cell) of all epidermal cells. Keratin filaments run within a cell from the inside of the outer membrane to weave a "basket" around the nucleus of the cell. Keratins are a principle part of the cells in the epidermis, hair, nails, feathers, hooves, horny tissues and the enamel of teeth.
Keratin accounts for 30% of the cellular protein of living epidermal cells and 85% of cellular protein of the dead cells in the stratum corunem (the scaly, dead or horny layer of the outer skin). In hair fiber, keratin proteins comprise 65-95% of the total hair fiber by weight. Each molecule of keratin is very small - about 10 nanometers across. To give you a sense of how small that is, 10,000 keratin molecules lined up side by side would cover the width of the average terminal scalp hair.
There are several subtypes of keratin proteins, some are called "soft" keratins and others are "hard" keratins. Basically, soft keratins are found in the skin and are relatively easy to break down whereas hard keratins are very resistant to degradation. Hard keratins do not dissolve in water and they are highly resistant to proteolytic enzymes. As you might have guessed, hair fiber is mostly made from hard keratin proteins.
Hair contains a high amount of sulfur because the amino acid cysteine is a key component of the keratin proteins in hair fiber. The sulfur in cysteine molecules in adjacent keratin proteins link together in disulfide chemical bonds. These disulfide bonds are very strong and very difficult to break apart. These disulfide chemical bonds linking the keratins together are the key factor in the durability and resistance of hair fiber to degradation under environmental stress. They are largely resistant to the action of acids but the disulfide bonds can be broken apart by alkali solutions. This property is exploited in perms and chemical hair straightening processes. Alkali is used to break the disulfide bonds in the keratins and make the hair weak. The hair is formed into a new shape and then acid is applied to neutralize the alkali and enable the disulfide bonds to reform. The reformed disulfide bonds hold the hair in its new shape.
Some cosmetics manufacturers claim to make hair products that contain keratin to strengthen hair or promote hair growth. However, the cells in hair follicles make all the keratin protein that they require from amino acids supplied via the blood. Eating keratin protein does not help hair growth. Eating hard keratins as found in hair fiber is pointless as they cannot be broken down and absorbed. The keratins simply pass straight through the gut. It would be much better to eat the constituent amino acids from which the hair follicle cells can make keratin. However, it is extremely rare in North America and Western Europe to have a deficiency in amino acids so severe that it affects hair fiber quality. Topically applying keratin to hair also has no long lasting effect. The keratins are mostly washed away in the shampooing process.
[FONT=Arial,Helvetica][SIZE=+1]What amino acids are present in hair fiber[/SIZE][/FONT]
Below is a table of the amino acids present in normal human hair in order of their quantity.
[FONT=Arial, Helvetica, sans-serif]Amino Acid[/FONT][FONT=Arial, Helvetica, sans-serif]Amount in residues extracted[/FONT]Cysteine17.5Serine11.7Glutamic acid11.1Threonine6.9Glycine6.5Leucine6.1Valine5.9Arginine5.6Aspartic acid5.0Alanine4.8Proline3.6Isoleucine2.7Tyrosine1.9Phenylalanine1.4Histidine0.8Methionine0.5
[FONT=Arial,Helvetica][SIZE=+1]What is the carbon, oxygen, hydrogen, nitrogen, and sulfur content of hair[/SIZE][/FONT]
In terms of raw elements, on average, hair is composed of 50.65% carbon, 20.85% oxygen, 17.14% nitrogen, 6.36% hydrogen, and 5.0% sulfur. Hair also contains trace amounts of magnesium, arsenic, iron, chromium and other metals and minerals.
[FONT=Arial,Helvetica][SIZE=+1]How many atoms are present in the average hair fiber diameter[/SIZE][/FONT]
The average scalp hair fiber diameter is between 80-120 micrometers. Hair fiber diameter varies depending on the location of the hair follicle, the ethnicity of the individual and the activity of hair diseases. An atom has a diameter 10 to the minus 10 meters. That's 0.0000000001m or 1 preceded by 9 zeros and a decimal point. So the diameter of the average hair fiber is ... er , umm, er ... (extensive counting of fingers and toes) ... 800,000 - 1,200,000 atoms. So the cross sectional area of a hair fiber asuming the cross section is circular (which is not always the case as curly hair as an oval cross section while straight hair has a circular cross section) contains 500,000,000,000 - 1,000,000,000,000 atoms. Remember the area of a circle is pi times the radius squared.
