In selecting amino acids to be used in the diet,is the optical activity of the acid important?explain your answer
The body largely has enzyme pathways that can work with L-isomers only.
<<Bryan Douglas Crawford
University of New Brunswick
I think the prevalence of L-amino acids in biological systems is a quirk of our evolutionary history; there's no reason D-amino acids wouldn't work chemically, but once early life forms started building proteins out of L-amino acids, L-amino acids became abundant an it became selectively advantageous to use L-amino acids because then you could use the amino acids you obtained by eating someone else. It's a matter of compatibility; if you use D-amino acids, you have to build them all from scratch, because you're not going to find them in your environment. As long as you use L-amino acids, you don't even need to maintain the de novo synthetic pathways; you can just eat something that has those pathways (hence the 'essential' dietary amino acids).>>
The optical activity of amino acids refers to their ability to rotate plane-polarized light either clockwise (dextrorotatory, +) or counterclockwise (levorotatory, -). In the context of selecting amino acids for the diet, the optical activity is not directly important.
However, the reason behind this lies in the biological activity of amino acids. Amino acids are the building blocks of proteins and are essential for various physiological functions in the human body. Both dextrorotatory and levorotatory amino acids are biologically active and can be utilized by the body in protein synthesis and other metabolic processes.
So, when selecting amino acids for the diet, the focus is usually on their nutritional content, essentiality, and specific functions rather than their optical activity. Nutritional requirements are generally based on the specific amino acids needed for protein synthesis and other metabolic functions in the body. Therefore, the optical activity of amino acids does not play a crucial role in their selection for the diet.