07/26/2026
How Your Body Creates Proteins
By Nucleus Medical Media
https://youtu.be/LCIkd-WwC7o?si=edFT6QX-AsxAxm8X
Science Direct
Amino Acids
In subject area:
Biochemistry, Genetics and Molecular Biology
Chapter
Amino Acids
2013, Brenner's Encyclopedia of Genetics (Second Edition)
By S. Maloy
Introduction
Amino acids are a class of important biomolecules that contain both amino groups and carboxylate groups (–COO−). In most contexts, the term ‘amino acids’ refers to the α-amino acids, so-called because both the amino and carboxyl groups are attached to the α-carbon. However, other types of amino acids are encountered in nature, such as the β-amino acids, in which the amino and carboxyl groups are attached to different carbons in the backbone.
All α-amino acids (with the exception of glycine) have four different substituents attached to the α-carbon and are therefore chiral molecules. Chirality, also called handedness, is a special subset of asymmetry describing objects that have no internal plane of symmetry and are not superimposable upon their own mirror image. Almost all of the amino acids found in nature have the same chirality with respect to the α-carbon and are referred to as l-amino acids based on chemical nomenclature guidelines. Their rare, stereoisomer, mirror-image counterparts are called d-amino acids. Just as your right hand will not fit properly into a left-hand glove, a d-amino acid will not fit properly in a space that fits an l-amino acid.
Although hundreds of amino acids have been identified or synthesized, 20 of these are often designated the common amino acids. In biological systems, these amino acids are the building blocks of proteins. Under the direction of messenger RNA during protein synthesis, the amino and carboxyl side chains of two amino acids are condensed chemically on the ribosome, which acts as an amino acid polymerase. This reaction releases water and is called peptide bond. Chains of amino acids linked in this manner are thus called polypeptides or, more simply, proteins.
Science Direct
Amino Acids
In subject area:
Biochemistry, Genetics and Molecular Biology
https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/amino-acids
National Library of Medicine
Biochemistry, Essential Amino Acids
Author Information and Affiliations
Authors
Michael J. Lopez; Shamim S. Mohiuddin.
Affiliations
Augusta Un., Medical College of Georgia
Imam Abdulrahman Bin Faisal University, Dammam
Introduction
Proteins are made up of 20 amino acids. Each amino acid has an α-carboxyl group, a primary α-amino group, and a side chain called the R group (Amino Acid Generic Structure). Unlike other amino acids, proline has a secondary amino group. The side chain varies from 1 amino acid to the other. Nutritionally, amino acids are divided into 3 groups—essential, nonessential, and semi-essential. Semi-essential amino acids are synthesized by the body but are designated essential during periods of stress.
Nine amino acids, including histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine, are classified as essential amino acids because they cannot be synthesized by human or other mammalian cells. Therefore, these amino acids must be supplied from an exogenous diet. The body synthesizes non-essential amino acids not primarily derived from the diet. Semi-essential amino acids are growth-promoting amino acids. They are essential in growing children, pregnant women, and lactating women. Amino acids are further classified into 3 groups depending on the structure of the R-group—neutral, acidic, and basic. In addition to serving as the building block of proteins and peptides, amino acids play crucial roles in various important functions.
Some amino acids are converted to carbohydrates and are called glucogenic amino acids. Certain amino acids give rise to specialized products. For example, tyrosine can be converted to hormones, such as thyroid hormones, epinephrine, norepinephrine, and melanin.
Methionine, in its active form known as S-adenosylmethionine, plays a critical role in cellular processes by transferring the methyl group to various substances through a process called transmethylation. Cystine and methionine are the primary sources of sulfur.
National Library of Medicine
Biochemistry, Essential Amino Acids
https://www.ncbi.nlm.nih.gov/books/NBK557845/
National Library of Medicine
Determining amino acid requirements in humans
Introduction
In the human body, protein is the chief functional and structural constituent in every cell. During development, dietary protein is necessary for growth plus maintenance and for maintenance alone during all other stages of life. The most important nutritional aspect of dietary protein are the consituent amino acids. Among the 20 amino acids that constitute human body protein 9 are indispensable (histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, valine), which means they cannot be made in the body and must be supplied in the diet. There are five dispensable amino acids (alanine, aspartic acid, asparagine, glutamic acid, serine) that can be synthesized in the body whereas the remaining six are conditionally indispensable (arginine, cysteine, glutamine, glycine, proline, tyrosine) meaning that they can be made by the body however their synthesis becomes limiting under specific conditions.
The Food and Agriculture Organization (FAO) have acknowledged that indispensable amino acids should be treated as individual nutrients since the amino acid composition of foods vary greatly and in vivo amino acids have various regulatory roles (i.e., precursors for coenzymes, hormones, nucleic acids and other molecules).
National Library of Medicine
Determining amino acid requirements in humans
https://pmc.ncbi.nlm.nih.gov/articles/PMC11291443/
National Library of Medicine
Diet and Health
Implications for Reducing Chronic Disease Risk
National Research Council (US) Committee on Diet and Health.
Washington (DC): National Academies Press (US); 1989.
Diet and Health examines the many complex issues concerning diet and its role in increasing or decreasing the risk of chronic disease. It proposes dietary recommendations for reducing the risk of the major diseases and causes of death today: atherosclerotic cardiovascular diseases (including heart attack and stroke), cancer, high blood pressure, obesity, osteoporosis, diabetes mellitus, liver disease, and dental caries.
8. Protein
Proteins account for about three-fourths of the dry matter in most human tissues other than bone and adipose tissue. They are macromolecules with molecular weights ranging from a few thousand to many millions, and they are required for practically every essential function in the body. From the standpoint of nutrition, the human body does not require dietary protein per se. Rather, it requires the nine essential amino acids that are present in dietary proteins. Dietary sources of utilizable carbon, usually from carbohydrates, and nitrogen are required for the synthesis of nonessential amino acids.
The nine essential amino acids are histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. They are deemed essential because they cannot be synthesized by mammals, at least in the amounts needed, and are therefore essential constituents of an adequate diet for humans.
National Library of Medicine
Diet and Health
https://www.ncbi.nlm.nih.gov/books/NBK218743/
Medical Herbalism -The Science And Practice Of Herbal Medicine
https://drive.google.com/file/d/1Ur3nSRObtMnbdG8rmxFngdNrjffowrub/view?usp=drivesdk
All Trees Shall Be For Meat
Ezekiel 47:12
12 And by the river upon the bank thereof, on this side and on that side, shall grow all trees for meat, whose leaf shall not fade, neither shall the fruit thereof be consumed. It shall bring forth new fruit according to his months, because their waters issued out of the sanctuary; and the fruit thereof shall be for meat and the leaf thereof for medicine.
His Strength Is In His Loins
Job 40:15-16
15 Behold now behemoth, which I made with thee; he eateth grass as an ox.
16 Lo now, his strength is in his loins, and his force is in the navel of his belly.