-behave like salts
-are crystalline solids with somewhat high melting points
-are mostly mostly hydrophilic
-& have a charge which changes with pH.
Amino acids exist as zwitterions (overall charge= zero). They are subunits of proteins and peptides (linked by peptide bonds) consisting of an Amine (NH3) and a carboxyl (COOH) functional group along with a “R” side chain that is unique to every amino acid in existence.
While there are generally 20 naturally-occurring amino acids (AA’s) in nature that can be directly coded by DNA, (yep, there are more in existence) it is estimated that there are a further 500 of these adorable guys. They can be found in any living organism; from the bacteria living inside your keyboard (which y’all should really clean more often) to the extremophile bacteria living in the hot water vents in Yellowstone National Park.
Of these naturally occurring amino acids, 10 of these are absolutely essential. Why? Our bodies can’t synthesize these on their own and must obtain them from the foods or supplements (shout to all our gym-junkies, we see your amino acid pill popping) that we consume.
In the body, AA’s can be synthesized from intermediates that are drawn from the citric acid cycle, the pentose phosphate pathway and the glycolic pathway. Also, they can be obtained from ketoacids and other biochemical pathways that exist in living organisms
Interestingly, AA synthesis is regulated by feedback inhibition, to put it simply, the final product (our adorable amino acids) are the enzyme inhibitors themselves by allosterically binding to (i.e. changing shape to fit) the enzymes’ active site.
Without this biochemical process occurring, high concentrations of amino acids would have very adverse effects on our bodies such as dehydration, weight gain, and potentially life threatening organ damage.
- memrise. “Pirates Favorite Amino Acid.” Digital image, 2013. http://static.memrise.com/img/400sqf/from/uploads/course_photos/38105_Pirates-Favorite-Amino-Acid_1856-l.jpg
- Berg, Jeremy M, John L Tymoczko, Lubert Stryer and Lubert Stryer. Biochemistry. New York: W.H. Freeman, 2002
- Van De Poll, Marcel CG, Peter B Soeters, Nicolaas EP Deutz, Kenneth CH Fearon and Cornelis HC Dejong. “Renal metabolism of amino acids: its role in interorgan amino acid exchange.” The American journal of clinical nutrition 79, no. 2 (2004): 185–197.
- Webmd.com. “Too Much Protein?.” n.d.. http://www.webmd.com/diet/news/20000425/protein-popularity
- Elmhurst.edu. “Amino Acids.” n.d.. http://www.elmhurst.edu/~chm/vchembook/560aminoacids.html
Contributors: Le Frenchie, Roi (editor)