CHAPTER 8
Building Blocks
PART 1
Amino Acids: “Building Blocks” of Protein
Amino acids are characterized as building blocks primarily because they are the structural units combined to make proteins. But the metaphor works a level or two deeper as well. Like a child’s play blocks, the amino acids can be stacked and grouped in many different ways with the potential for a broad assortment of protein constructions. READ MORE
Moreover, once a construction is erected, it can then be deconstructed without destroying the individual pieces — and the pieces used again to create entirely new structures.
In the process of protein metabolism, the amino acid blocks are repeatedly disassembled and reassembled. The destructive and constructive phases (catabolism and anabolism, respectively) give shape, form, and purpose to the proteins that make life possible.
The Amino Acid Family
Though over 500 amino acids have been discovered in nature, just 20 of them are integral to our constitution.
| Nonessential Amino Acids | Essential Amino Acids |
| Alanine | Valine |
| Arginine | Leucine |
| Glutamine | Isoleucine |
| Aspartic Acid | Lysine |
| Glutamate | Threonine |
| Proline | Methionine |
| Cysteine | Histidine |
| Tyrosine | Phenylalanine |
| Asparagine | Tryptophan |
| Glycine | |
| Serine |
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PART 2
Amino Acid Multiplication
The twenty amino acids can be conjoined and reordered in so many varieties as to yield hundreds of thousands of different protein types. With just two amino acids joined by a single peptide bond, constituting a dipeptide chain, there are 400 possible combinations. READ MORE
With three amino acids (a tripeptide), 8000 combinations. Variables include the number and type of amino acids combined; their sequence along a chain; the number of peptide bonds linking them together; the shapes assumed as polypeptide chains fold; and the three-dimensional structure of a chain or of multiple chains linked together. LESS