The DNA strands (nucleic acids) are bound up by proteins such as histones, together forming chromatin.  The basic repeating unit of chromatin is known as a nucleosome, and when further complexed with an H1 histone protein, becomes a chromatosome.   This jumble is the basis of chromosomes.  Different sections of the chromosomes, at intervals, are chains of code distinguished as individual genes.    

 

Each gene may encode a different enzyme, or an entire polypeptide chain…

 

While the rest of the story of DNA and genetics is a fascinating one, it is beyond the scope of this discussion.  The purpose of involving DNA and RNA so far was to serve as an illustration of a way to think about some of the components of polypeptide chains and proteins.  This basic understanding, along with a knowledge of the role of enzymes, helps us appreciate how the uptake of nutrition begins to take place in plant roots, and through the intestinal walls of higher organisms.  Furthermore, comprehending what is meant by chelation, and to appreciate how this process enhances an organism’s ability to assimilate essential minerals and trace elements, requires a fundamental understanding of amino acids and proteins in order to not talk nonsense when parroting serious bits of information to chemists, botanists, veterinarians and MDs.

 

 

 

 

 PEPTIDES,  POLYPEPTIDE  CHAINS,  AND  PROTEINS:

 

 

As we have observed, three individual nucleotides in a chain make an Amino Acid, and three or more nucleotides, are called Polynucleotides.  These polynucleotides are bonded together in turn, to form Polypeptide Chains.  The order in which Amino Acids (groups of three nucleotides) are strung together makes up genetic code. 

 

Reverting to DNA once again, it is termed a macromolecule, also known as a polymer because it is relatively long.  Since one or more Polypeptide Chains constitute(s) a Protein, it follows that Proteins, just like nucleic acid, are also made up of Amino acids.  That is why meat, being a source of protein, is a primary source for amino acids.  Some proteins consist of only a few amino acids, whereas others may have thousands [Pierce (2003), p. 409].

 

A mere peptide then, is a “short polymer”, usually just two to ten units long of Amino Acids. http://www.visionlearning.com/library/module_viewer.php?mid=62  Hence, multiple peptides connected together in a longer, polymer chain, are called “polypeptide chains”.  Individual peptides are joined together by a peptide bond.

 

Example  of  a  Peptide  Bond     

Also, when two amino acids (components of peptides) bond together, the two ends of adjacent amino acids (corresponding counterparts remaining on opposite molecules are shown in red) are released.  What was formerly a carboxyl group (COH) is separated in this process, and the Nitrogen atom at the left end of one amino acid molecule, binds to the remaining Carbon atom on the right hand side of the other molecule, forming the peptide bond, as illustrated to the left

 

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