Amino Acids

Amino Acids: Amino acids are the essential components of proteins. They are organic compounds that contain both an amino group (-NH_₂) and a carboxyl group (-COOH). These molecules are often referred to as the “building blocks” of proteins due to their key role in protein synthesis. Amino acids are also necessary for producing enzymes, certain hormones, and neurotransmitters. There are commonly 20 amino acids found in proteins, each with a distinct chemical structure that influences the overall characteristics of the protein.

Amino Acids Structure

Each amino acid contains a central carbon atom, known as the alpha carbon. This alpha carbon is connected to the following groups:

• A carboxyl group (-COOH)
• An amino group (-NH₂)
• A hydrogen atom (-H)
• A side chain, called the R group

The R group is different for each amino acid and is responsible for its specific characteristics and function.

Also Check: Amino Acids Formula

Classification of Amino Acids

Amino acids are the fundamental components of proteins and can be categorized based on whether the body can produce them or not.

Essential Amino Acids

Essential amino acids are those that the body cannot make on its own. These must be obtained from food sources. They play a vital role in several functions, such as protein synthesis, muscle development, and tissue repair. The 9 essential amino acids list are:

• Histidine
• Isoleucine
• Leucine
• Lysine
• Methionine
• Phenylalanine
• Threonine
• Tryptophan
• Valine

Arginine is considered conditionally essential in certain situations, particularly during periods of growth and development.

Nonessential Amino Acids

Nonessential amino acids, in contrast, are produced by the body from other amino acids or compounds. Though the body can synthesize these, extra intake may be needed during specific circumstances like growth, illness, or recovery from injury. The 11 nonessential amino acids list are:

• Alanine
• Asparagine
• Aspartic acid
• Cysteine
• Glutamic acid
• Glutamine
• Glycine
• Proline
• Serine
• Tyrosine

Amino Acids Functions

Amino acids are vital for many important functions in the human body. Some key Amino Acids benefits are as follows:

1. Tissue Building and Repair: Amino acids form proteins, which are necessary for the growth and repair of body tissues.
2. Enzyme and Hormone Formation: They help in producing enzymes and hormones that control various bodily processes.
3. Supporting the Immune System: Amino acids aid in the creation of antibodies, which are essential for maintaining a strong immune system.
4. Energy Source: When carbohydrates and fats are unavailable, amino acids can provide energy for the body.
5. Nutrient Transport: They assist in moving nutrients throughout the body to where they are needed.
6. Neurotransmitter Production: Amino acids are involved in creating neurotransmitters, which help send signals in the brain.
7. Maintaining Healthy Skin, Hair, and Nails: They contribute to the upkeep and health of skin, hair, and nails.

Amino Acids Examples

Proteins are primarily made up of 20 standard amino acids. In addition to these, there are less common amino acids that may appear in specific proteins or be modified after the protein is formed. Here are some examples of amino acids:

1. Alanine (Ala): A nonpolar amino acid with a simple methyl group as its side chain.
2. Glycine (Gly): The smallest amino acid, having just a hydrogen atom as its side chain.
3. Valine (Val): A nonpolar amino acid with a branched side chain.
4. Leucine (Leu): A nonpolar amino acid with a branched side chain.
5. Isoleucine (Ile): Another nonpolar amino acid with a branched side chain.
6. Proline (Pro): A unique amino acid with a cyclic structure.
7. Phenylalanine (Phe): A nonpolar amino acid with a phenyl ring in its side chain.
8. Tyrosine (Tyr): A polar amino acid with a phenol group in its side chain.
9. Tryptophan (Trp): A nonpolar amino acid with an indole ring in its side chain.
10. Serine (Ser): A polar amino acid with a hydroxyl group as its side chain.
11. Threonine (Thr): A polar amino acid, also with a hydroxyl group in its side chain.
12. Asparagine (Asn): A polar amino acid with an amide group in its side chain.
13. Glutamine (Gln): A polar amino acid with an amide group in its side chain.
14. Aspartic acid (Asp): A polar amino acid with a carboxyl group in its side chain.
15. Glutamic acid (Glu): A polar amino acid with a carboxyl group in its side chain.
16. Lysine (Lys): A positively charged amino acid with an amino group in its side chain.
17. Arginine (Arg): A positively charged amino acid with a guanidino group in its side chain.
18. Histidine (His): A positively charged amino acid with an imidazole ring in its side chain.
19. Cysteine (Cys): A polar amino acid with a thiol group, which can form disulfide bonds.
20. Methionine (Met): A nonpolar amino acid that contains sulfur in its side chain.

How Much Amino Acid Intake is Necessary?

It is not necessary to eat foods with amino acids at every meal, but it is important to maintain a balance of them throughout the day. The daily recommended intake for each essential amino acid, based on 2.2 pounds (1 kilogram) of body weight, is as follows:

• Histidine: 14 milligrams
• Leucine: 42 milligrams
• Isoleucine: 19 milligrams
• Threonine: 20 milligrams
• Phenylalanine: 33 milligrams
• Lysine: 38 milligrams
• Methionine: 19 milligrams
• Tryptophan: 5 milligrams
• Valine: 24 milligrams

Best Food Sources of Amino Acids

Essential amino acids are found in various foods, particularly in animal proteins like beef, poultry, and eggs. Animal proteins are the most easily absorbed by your body.

• Complete Proteins: Foods that contain all nine essential amino acids are called complete proteins, examples of which include beef, poultry, fish, eggs, dairy, soy, quinoa, and buckwheat.
• Incomplete Proteins: On the other hand, foods that contain some but not all essential amino acids are known as incomplete proteins. These include nuts, seeds, beans, and certain grains.

For individuals following vegetarian or vegan diets, it is important to consume a variety of incomplete proteins to ensure that all nine essential amino acids are obtained.

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Should I Take Amino Acid Supplements?

A balanced diet usually provides all the essential amino acids your body needs. Some people take amino acid supplements to improve sleep, mood, or athletic performance. However, the U.S. Food and Drug Administration (FDA) does not approve these supplements. Consult your healthcare provider before starting any supplements, including amino acids, is best.

FAQs on Amino Acids

What is an amino acid and its function?

Amino acids are organic compounds that serve as the building blocks of proteins. They play a essential role in protein synthesis, enzyme production, and various metabolic pathways in the body.

What are 20 amino acids?

The 20 amino acids are: alanine, arginine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine, and valine.

What are the 9 essential amino acids?

The 9 essential amino acids are: histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. These cannot be synthesized by the body and must be obtained from the diet.

How many amino acids are there?

There are 20 standard amino acids that are impotant for human biology.

What are the 11 non-essential amino acids?

The 11 non-essential amino acids are: alanine, arginine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, proline, serine, and tyrosine. These can be synthesized by the body.