Introduction to amino acids | Macromolecules | Biology | Khan Academy


Introduction to amino acids | Macromolecules | Biology | Khan Academy

Understanding amino acids and their role in the Central Dogma of Molecular Biology (how the information in DNA eventually gets expressed as chains of amino acids). Thinking about the amino and carboxyl groups and how amino acids are typically found as zwitterions at physiological pH. How amino acid side chains can impact protein structure.

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Proteins for Hair Growth

Protein and amino acids for hair growth
Many people ask me what proteins are most appropriate for hair growth. People with hair loss often turn to protein and amino acid supplements as part of their treatment regime. Although it is rare for a lack of protein to be a primary cause of hair loss, there is no harm in taking extra protein or amino acid supplements if you wish for your hair growth. If you take a blood test your serum total protein should be between 60–80 grams per liter. Less than this suggests a problem with protein intake. And you may take some of the protein supplements now available as either as powder protein supplements or liquid protein supplements. Soya bean protein is considered good for hair growth but take care not to take it in excess other wise it can have some negative affect.

Amino acids and proteins
Much importance has been given to proteins for hair growth. Protein serves as the major structural component of all cells in the body, and functions as enzymes, in membranes, as transport carriers, and as some hormones. During digestion and absorption dietary proteins are broken down to amino acids which serve as the building blocks for formation of structural proteins and functional compounds of protein such as enzymes and pre cursors of hormones etc. There are 20 amino acids in all which are required for the synthesis of proteins.

Proteins for hair growth
But out of which some of the amino acids cannot be synthesized by the body and are therefore are required to be taken as dietary amino acid supplements if you wish to take them to stimulate your hair growth. The amino acids: Phenylalanine, Valine, Tryptophan, Threonine, Isoleucine, Methionine, Histidine Arginine, Lysine Leucine are considered to be essential amino acids. But the distinction between essential and non-essential amino acids is not very clear, as some amino acids can be produced from others. For example the sulfur containing amino acids, methionine and homocysteine can be converted into each other but neither can be synthesized de novo in humans. Likewise, cysteine can be synthesized from homocysteine, but not otherwise. So, for convenience, sulfur-containing amino acids are sometimes considered a single pool of nutritionally-equivalent amino acids.

Hair follicles photo

Photo by AMagill

Hair follicles require a constant supply of amino acids via the blood stream to maintain hair growth. Hair follicles contain some of the fastest growing and dividing cells in the body so their energy, vitamin, mineral, and amino acid consumption is high. If amino acids are lacking, particularly the essential amino acids listed above, the hair follicles may be less able to produce hair fiber.

Benefits of amino acids

amino acids photo

Photo by Bioreg images

A lack of amino acids in a first world country diet is very unusual and for the most part supplements are not required. However, everyone should ensure they have a healthy, balanced diet that provides all the amino acids required. There are many amino acids, but the nine amino acids which are known as essential amino acids must be provided in the diet and are indispensable amino acids which are required for both hair and other functions of the body. The body can make the other 11 amino acids needed to synthesize specific structures from the nine essential amino acids and carbohydrate precursors.

Protein supplements

protein supplement photo

Photo by SocialAlex

Proteins from animal sources, such as meat, poultry, fish, eggs, milk, cheese, and yogurt, provide all nine indispensable amino acids in adequate amounts and for this reason are considered “complete proteins”. Proteins from plants, legumes, grains, nuts, seeds, and vegetables tend to be deficient in one or more of the indispensable amino acids and are called ‘incomplete proteins’. Vegetarian and vegan diets may contain enough protein, but people following these diets may not be receiving all the essential amino acids if they do not pay attention to the type of protein they eat. Vegan diets adequate in total protein content can be “complete” by combining sources of incomplete proteins which lack different indispensable amino acids.

Amino acid function for hair
In terms of hair fiber production, the most important amino acid is cysteine. Cysteine is the most common amino acid in hair. It is particularly important because it contains sulfur molecules. As part of a keratin protein chain, these sulfur molecules cross link with each other to produce disulfide bonds. These chemical bonds are what gives hair its strength. For this reason the most popular amino acid supplement taken for hair is cysteine.

Besides the proteins, nutritional diet vitamin supplements and safe herbal supplements are the best diet supplements for hair growth.

13 thoughts on “Introduction to amino acids | Macromolecules | Biology | Khan Academy

  1. santino zapiain

    If the R chain is hidrofilic because the variance of electonegativity between the oxygen and the hydrogen; it means that the carboxyl group is also hidrofilic?


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