20 Days of Amino Acids intro

Tomorrow I’m kicking off the bumbling biochemist’s version of an advent calendar - #20DaysOfAminoAcids! Each day I’m going to bring you the story of one of the 20 (common) amino acids - what we know about it and how we know about it, where it comes from, where it goes, and outstanding questions nobody knows.  
 
Proteins are our body’s main biochemical workhorses and they’re written in “letters” called amino acids. Amino acids have generic “amino” (NH₃⁺/NH₂) & “carboxyl” (COOH/COO⁻) groups that let them link up together through peptide bonds (N links to C, H₂O lost, and the remaining “residual” parts are called residues). The reason for the “2 options” in parentheses is that, as we’ll go into more below, these groups’ protonation state (how many protons (H⁺ ) they have depends on the pH (which is a measure of how many free H⁺ are around to take). 
 
Those generic parts are attached to a central “alpha carbon” (Ca), which is also attached to one of 20 unique side chains (“R groups”) which sticks off the peptide backbone (kinda like a charm sticking off a charm bracelet). The different “charms” have different properties (big, small, hydrophilic (water-loving), hydrophobic (water-avoiding), etc.) & proteins have different combos of them, so the proteins have different properties. Each amino acid has a backstory - a current story - and a future story. And I want to help tell these stories and maybe even make them part of the holiday “classics” 
 
 
                             

[SidhantJattan]

Thank you. I am a high school student from India and I have cleared NSEB ( the first level of international biology olympiad) and now I have my INBO ( 2nd level ) on 2nd February and for revision I just started to watch your series of Amino acids and thank God you started it again.

[sajjanvirdee]

Yesss let’s

Seriously thanks I’ve been wanting to learn the amino acids for a while this seems like a good way to start