Strings of amino acids make up proteins, of which there are countless varieties. Of the 2. 0 amino acids required for manufacturing the proteins the human body needs, the body itself produces only 1. This is just one example of the importance of amino acids in the functioning of life. Another cautionary illustration of amino acids' power is the gamut of diseases (most notably, sickle cell anemia) that impair or claim the lives of those whose amino acids are out of sequence or malfunctioning. Once used in dating objects from the distant past, amino acids have existed on Earth for at least three billion years—long before the appearance of the first true organisms. HOW IT WORKSA . In addition to those two elements, they include nitrogen, oxygen, and, in a few cases, sulfur. The basic structure of an amino- acid molecule consists of a carbon atom bonded to an amino group (- NH2), a carboxyl group (- COOH), a hydrogen atom, and a fourth group that differs from one amino acid to another and often is referred to as the- R group or the side chain. ![]() ![]() The- R group, which can vary widely, is responsible for the differences in chemical properties. This explanation sounds a bit technical and requires a background in chemistry that is beyond the scope of this essay, but let us simplify it somewhat. Imagine that the amino- acid molecule is like the face of a compass, with a carbon atom at the center. Raying out from the center, in the four directions of the compass, are lines representing chemical bonds to other atoms or groups of atoms. These directions are based on models that typically are used to represent amino- acid molecules, though north, south, east, and west, as used in the following illustration, are simply terms to make the molecule easier to visualize. To the south of the carbon atom (C) is a hydrogen atom (H), which, like all the other atoms or groups, is joined to the carbon center by a chemical bond. To the north of the carbon center is what is known as an amino group (- NH2). In the structure shown at the top of the page, R represents a side chain specific to each amino acid. The carbon atom next to the carboxyl group (which is therefore. Amino acids are the basic building blocks of the body. They are also sources of energy, like fats and carbohydrates. However, amino acids are structurally. AMINO ACID COMPLEX Articles by a Naturopathic Doctor (N.D.) Last Updated: August 12th, 2015 When you're feeling fatigued or weak. List of Amino Acids Needed by Your Body. Amino acids are one of the central chemicals needed by the body to function well. The Biology Project > Biochemistry > The Chemistry of Amino Acids. Basic Structure of Amino Acids Acidic & Amides Aliphatic. The hyphen at the beginning indicates that such a group does not usually stand alone but normally is attached to some other atom or group. To the east is a carboxyl group, represented as- COOH. In the amino group, two hydrogen atoms are bonded to each other and then to nitrogen, whereas the carboxyl group has two separate oxygen atoms strung between a carbon atom and a hydrogen atom. Hence, they are not represented as O2. Finally, off to the west is the R - group, which can vary widely. It is as though the other portions of the amino acid together formed a standard suffix in the English language, such as - tion. To the front of that suffix can be attached all sorts of terms drawn from root words, such as educate or. The variation in the terms attached to the front end is extremely broad, yet the tail end, - tion, is a single formation. Likewise the carbon, hydrogen, amino group, and carboxyl group in an amino acid are more or less constant. A FEW ADDITIONAL POINTS. The name amino acid, in fact, comes from the amino group and the acid group, which are the most chemically reactive parts of the molecule. Each of the common amino acids has, in addition to its chemical name, a more familiar name and a three- letter abbreviation that frequently is used to identify it. In the present context, we are not concerned with these abbreviations. Amino- acid molecules, which contain an amino group and a carboxyl group, do not behave like typical molecules. Instead of melting at temperatures hotter than 3. Interestingly, nearly all of the amino acids occurring in nature are the left- hand versions of the molecules, or the L- forms. They also are found in some antibiotics, among them, streptomycin, actinomycin, bacitracin, and tetracycline. These antibiotics, several of which are well known to the public at large, can kill bacterial cells by interfering with the formation of proteins necessary for maintaining life and for reproducing. Amino Acids and Proteins. Amino acids are the. Essential Amino Acids. Amino acids are organic compounds which contain both an amino group and a carboxyl group. According to Tillery, et al., the human body can. This is an explanation of what essential amino acids are and a list of the essential amino acids for humans. What Is an Essential Amino Acid? An essential amino acid. Index Biochemical concepts. A chemical reaction that is characteristic of amino acids involves the formation of a bond, called a peptide linkage, between the carboxyl group of one amino acid and the amino group of a second amino acid. Very long chains of amino acids can bond together in this way to form proteins, which are the basic building blocks of all living things. The specific properties of each kind of protein are largely dependent on the kind and sequence of the amino acids in it. Other aspects of the chemical behavior of protein molecules are due to interactions between the amino and the carboxyl groups or between the various R - groups along the long chains of amino acids in the molecule. NUMBERS AND COMBINATIONS. Amino acids function as monomers, or individual units, that join together to form large, chainlike molecules called polymers, which may contain as few as two or as many as 3,0. Groups of only two amino acids are called dipeptides, whereas three amino acids bonded together are called tripeptides. If there are more than 1. All the millions of different proteins in living things are formed by the bonding of only 2. Like the 2. 6 letters of the alphabet that join together to form different words, depending on which letters are used and in which sequence, the 2. But whereas words usually have only about 1. Because each amino acid can be used many times along the chain and because there are no restrictions on the length of the chain, the number of possible combinations for the formation of proteins is truly enormous. There are about two quadrillion different proteins that can exist if each of the 2. Just as not all sequences of letters make sense, however, not all sequences of amino acids produce functioning proteins. Some other sequences can function and yet cause undesirable effects, as we shall see. REAL- LIFE APPLICATIONSDNA (deoxyribonucleic acid), a molecule in all cells that contains genetic codes for inheritance, creates encoded instructions for the synthesis of amino acids. In 1. 98. 6, American medical scientist Thaddeus R. Dryja (1. 94. 0- ) used amino- acid sequences to identify and isolate the gene for a type of cancer known as retinoblastoma, a fact that illustrates the importance of amino acids in the body. Amino acids are also present in hormones, chemicals that are essential to life. Among these hormones is insulin, which regulates sugar levels in the blood and without which a person would die. Another is adrenaline, which controls blood pressure and gives animals a sudden jolt of energy needed in a high- stress situation—running from a predator in the grasslands or (to a use a human example) facing a mugger in an alley or a bully on a playground. Biochemical studies of amino- acid sequences in hormones have made it. Amino Acids and Nutrition. Just as proteins form when amino acids bond together in long chains, they can be broken down by a reaction called hydrolysis, the reverse of the formation of the peptide bond. That is exactly what happens in the process of digestion, when special digestive enzymes in the stomach enable the breaking down of the peptide linkage. Each individual cell of the organism then can use these amino acids to assemble the new and different proteins required for its specific functions. Life thus is an ongoing cycle in which proteins are broken into individual amino- acid units, and new proteins are built up from these amino acids. ESSENTIAL AMINO ACIDS. Out of the many thousands of possible amino acids, humans require only 2. Two others appear in the bodies of some animal species, and approximately 1. Considering the vast numbers of amino acids and possible combinations that exist in nature, the number of amino acids essential to life is extremely small. Yet of the 2. 0 amino acids required by humans for making protein, only 1. Most proteins from animal sources, gelatin being the only exception, contain all the essential amino acids and are therefore considered complete proteins. On the other hand, many plant proteins do not contain all of the essential amino acids. For example, lysine is absent from corn, rice, and wheat, whereas corn also lacks tryptophan and rice lacks threonine. Soybeans are lacking in methionine. Vegans, or vegetarians who consume no animal proteins in their diets (i. Amino Acids, Health, and Disease. Amino acids can be used as treatments for all sorts of medical conditions. For example, tyrosine may be employed in the treatment of Alzheimer's disease, a condition characterized by the onset of dementia, or mental deterioration, as well as for alcohol- withdrawal symptoms. Taurine is administered to control epileptic seizures, treat high blood pressure and diabetes, and support the functioning of the liver. Numerous other amino acids are used in treating a wide array of other diseases. Sometimes the disease itself involves a problem with amino- acid production or functioning. In the essay Vitamins, there is a discussion of pellagra, a disease resulting from a deficiency of the B- group vitamin known as niacin. Pellagra results from a diet heavy in corn, which, as we have noted, lacks lysine and tryptophan. Its symptoms often are described as the . Thanks to a greater understanding of nutrition and health, pellagra has been largely eradicated, but there still exists a condition with almost identical symptoms: Hartnup disease, a genetic disorder named for a British family in the late 1. Hartnup disease is characterized by an inability to transport amino acids from the kidneys to the rest of the body. The symptoms at first seemed to suggest to physicians that the disease, which is present in one of about 2. Tests showed that sufferers did not have inadequate tryptophan levels, however, as would have been the case with pellagra. On the other hand, some 1. Hartnup disease sufferers, indicating that rather than properly transporting amino acids, their bodies are simply excreting them. This is a potentially very serious condition, but it can be treated with the B vitamin nicotinamide, also used to treat pellagra.
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