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( Protein)
Proteins are large organic compounds made of amino acids arranged in a linear chain and joined together by peptide bonds between the carboxyl and amino groups of adjacent amino acid residues. The sequence of amino acids in a protein is defined by a gene and encoded in the genetic code. Although this genetic code specifies 20 "standard" amino acids plus selenocysteine and - in certain archaea - pyrrolysine, the residues in a protein are sometimes chemically altered in post-translational modification either before the protein can function in the cell, or as part of control mechanisms. Proteins can also work together to achieve a particular function, and they often associate to form stable complexes.[1] Like other biological macromolecules such as polysaccharides and nucleic acids, proteins are essential parts of organisms and participate in every process within cells. Many proteins are enzymes that catalyze biochemical reactions and are vital to metabolism. Proteins also have structural or mechanical functions, such as actin and myosin in muscle and the proteins in the cytoskeleton, which form a system of scaffolding that maintains cell shape. Other proteins are important in cell signaling, immune responses, cell adhesion, and the cell cycle. Proteins are also necessary in animals' diets, since animals cannot synthesize all the amino acids they need and must obtain essential amino acids from food. Through the process of digestion, animals break down ingested protein into free amino acids that are then used in metabolism. The word protein comes from the Greek word p??ta ("prota"), meaning "of primary importance." Proteins were first described and named by the Swedish chemist Jöns Jakob Berzelius in 1838. However, the central role of proteins in living organisms was not fully appreciated until 1926, when James B. Sumner showed that the enzyme urease was a protein.[2] The first protein to be sequenced was insulin, by Frederick Sanger, who won the Nobel Prize for this achievement in 1958. The first protein structures to be solved included hemoglobin and myoglobin, by Max Perutz and Sir John Cowdery Kendrew, respectively, in 1958.[3][4] The three-dimensional structures of both proteins were first determined by x-ray diffraction analysis; Perutz and Kendrew shared the 1962 Nobel Prize in Chemistry for these discoveries. Proteins are linear polymers built from 20 different L-a-amino acids. All amino acids possess common structural features, including an a carbon to which an amino group, a carboxyl group, and a variable side chain are bonded. Only proline differs from this basic structure as it contains an unusual ring to the N-end amine group, which forces the CO–NH amide moiety into a fixed conformation.[5] The side chains of the standard amino acids, detailed in the list of standard amino acids, have different chemical properties that produce three-dimensional protein structure and are therefore critical to protein function. The amino acids in a polypeptide chain are linked by peptide bonds formed in a dehydration reaction. Once linked in the protein chain, an individual amino acid is called a residue, and the linked series of carbon, nitrogen, and oxygen atoms are known as the main chain or protein backbone. The peptide bond has two resonance forms that contribute some double-bond character and inhibit rotation around its axis, so that the alpha carbons are roughly coplanar. The other two dihedral angles in the peptide bond determine the local shape assumed by the protein backbone.
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Protein Subcategories
Protein Articles
The Power of Protein: Part 1 by Quentilla Alton
The human body has many times been described as the most incredible, complex machine in the world. There are many essential “fuels” required to ensure that this machine runs smoothly and efficiently: water, many various vitamins, minerals, and trace ...
Fighting Fatigue by Sandra Powers
Fighting Fatigue by Sandy Powers
My daughter was complaining how tired she is. Kay is in her middle thirties and had just started a new job in Human Resources.
“I am so tired, “she sighed. “I’m dragging through the day. I’m...
3 Secrets To Dramatically Melt Fat by Lucas Wold
In my secret Fat Loss Files program, you’ve seen that to lose weight effectively you need fiber-rich fruits and veggies, lean proteins, and high-fiber starches in your diet.
Fruits and vegetables are all over the place. Bananas, apples, pinea...
Weight Loss Protein, Weight-Control Powders by Dr.George Scheele
By Eve Kelly | Published Wednesday, July 30, 2008
'It's like my body flipped a switch and started storing fat," lamented my husband Patrick as he stood in front of the mirror. "Ever since I turned 35, the battle of the bulge has turned into ...
Eat Protein Breakfast and Lose Weight Fast by Jenny George
http://www.getweightlossdiet.com/
Protein contain breakfast is a good choice to start a day with power. Many people, when starting weight loss just skip there breakfast but this is like to start...
Protein To Building Muscle While Losing Fat by Jerold Smith
Protein has always been an essential source of nutrient for body building especially for the past 5 years where the public has been more exposed to diets of low carbs that includes a high protein portion.
Body builders and trainers must eat p...
Supplement Your Weight Loss Diet with Whey Protein by Michael Podlesny
Protein is obviously a very important part of any nutrition program for someone who is working out with weights and trying to build muscle volume.
You may have read in previous articles that I have written the importance of increasing your mu...
Bodybuilding Workout Methods by Blake Johnson
A visible increase in the size of the muscles and also muscular strength is the main benefit of bodybuilding workout or routine. Muscles grow in size and have increased power when you work out with weights. If the weights used in the workout are not ...
The Atkins Diet Reemeges by jeff behar
Dr.Robert Atkins addressed his own weight condition from a diet he read in the Journal of the American Medical Association. Realizing the benefits of the diet he followed Atkins later popularized the idea as The Atkins Diet in a series of books, st...
The Truth of The Biggest Loser Diet by jeff behar
The Biggest Loser Diet is a calorie-controlled, carbohydrate modified, fat reduced, weight loss diet geared to help you burn pure fat from the body. It also help to do so without deprivation or loss of energy.
How The Biggest Loser Die...
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