http://www.chem.ucalgary.ca/courses/351/Carey5th/Ch27/ch27-1-4-2.html

... of pKa and pI values. The pKa values and the isoelectronic point, pI, are given below for the 20 α-amino acids. pKa1= α-carboxyl group, pKa2 = α-ammonium ion, and pKa3 = side chain group. ... Serine, 2.21, 9.15, ---, 5.68. Threonine, 2.09  ...

http://www.chem.ucla.edu/~rebecca/153A/amino_acids.pdf

Tyrosine (hydroxyl): 10.5. Lysine (amino):. 10.5. Arginine (guanidino): 12.5. Serine (hydroxyl):. 13. Threonine (hydroxyl): 13 α-carboxyl of free amino acid: 2.

https://www.anaspec.com/html/pK_n_pl_Values_of_AminoAcids.html

pK and pl Values of Amino Acids ... Serine. 2.21. 9.15. 5.68. Threonine. 2.15. 9.12 . 5.60. Tryptophan. 2.38. 9.39. 5.88. Tyrosine. 2.20. 9.11. 10.07. 5.63. Valine.

https://en.wikipedia.org/wiki/Serine

Serine (symbol Ser or S) is an ɑ-amino acid that is used in the biosynthesis of proteins. It contains an α-amino group a carboxyl group (which is in the ...

http://www.thinkpeptides.com/aminoacidproperties.html

Serine. Ser. S. Polar. Neutral. -0.8. 105.09. 5.68. Threonine. Thr. T. Polar ... ** Isoelectric Point: the pH at which the net charge of the amino acid is equal to zero .

https://www.rose-hulman.edu/~brandt/Chem330/Amino_acids.pdf

Phenylalanine is a non-polar amino acid; while tyrosine and tryptophan are ... pKa value of the side-chain is ~4 for both of these compounds (the pKa value is.

https://www.sigmaaldrich.com/life-science/metabolomics/learning-center/amino-acid-reference-chart.html

Discover our full product line of amino acids, including Alanine, Isoleucine, ... Tryptophan, Tyrosine, Aspargine, Cysteine, Glutamine, Methionine, Serine, ... 1 pKa is the negative of the logarithm of the dissociation constant for the -COOH group.

https://pubchem.ncbi.nlm.nih.gov/compound/Serine

Serine | C3H7NO3 | CID 5951 - structure, chemical names, physical and chemical properties, ... Serine is also found at the active site of the serine protease enzyme class that includes trypsin and chymotrypsin. ..... pKa = 2.21; pKb = 9.15.

https://proteinstructures.com/Structure/Structure/amino-acids.html

Polar amino acids include serine and threonine (contain a hydroxyl group), asparagine and glutamine ... It has two –NH group with a pKa value of around 6.

https://biochem.science.oregonstate.edu/files/biochem/ahern/Teaching_Powerpoint/Amino%20Acids.pptx

Building Blocks of Proteins; Essential Amino Acids; Basic Structure; Stereochemistry; Side Chain Chemistry ... Alanine, Aspartic Acid, Arginine, Phenylalanine, Serine, Asparagine ... Name, Charged R-group, Approximate R- group pKa.