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Amino acids differ from each other with respect to their side chains, which are referred to as R groups. The R group for each of the amino acids will differ in structure, electrical charge, and polarity. Refer to the charts and structures below to explore amino acid properties, types, applications, and availability.


pKa Data Compiled by R. Williams page-1 pKa Values INDEX Inorganic 2 Phenazine 24 Phosphates 3 Pyridine 25 Carboxylic acids 4, 8 Pyrazine 26 Aliphatic 4, 8 Aromatic 7, 8 Quinoline 27 Phenols 9 Quinazoline 27 Alcohols and oxygen acids 10, 11 Quinoxaline 27 Amino Acids 12 Special Nitrogen Compounds 28 Peptides 13 Hydroxylamines 28


The α-carboxylic acid group of amino acids is a weak acid, meaning that it releases a hydron (such as a proton) at moderate pH values.In other words, carboxylic acid groups (−CO 2 H) can be deprotonated to become negatively charged carboxylates (−CO 2 −).The negatively charged carboxylate ion predominates at pH values greater than the pKa of the carboxylic acid group (typically around 2 ...

clas.sa.ucsb.edu/staff/Resource Folder/Chem109ABC/Acid, Base Strength/Table of Acids w...

Table of Acids with Ka and pKa Values* CLAS * Compiled from Appendix 5 Chem 1A, B, C Lab Manual and Zumdahl 6th Ed. The pKa values for organic acids can be found in


Table of pK a and pI values. The pK a values and the isoelectronic point, pI, are given below for the 20 α-amino acids.; pKa 1 = α-carboxyl group, pK a 2 = α-ammonium ion, and pK a 3 = side chain group.


Amino Acid pKa Values and Side Chain Identities Amino Acid pKa Values α-CO 2H α-NH 3+ Side Side Chain (Z) – “fully” protonated Alanine 2.34 9.69 –CH 3 Arginine 2.17 9.04 12.48 H 2NCNHCH 2CH 2CH 2Ð NH2 Asparagine 2.02 8.84 H2NCCH2Ð O Aspartic Acid 2.09 9.82 3.86 –CH 2CO 2H Cysteine 1.71 10.78 8.33 –CH 2SH


In computational biology, protein pK a calculations are used to estimate the pK a values of amino acids as they exist within proteins.These calculations complement the pK a values reported for amino acids in their free state, and are used frequently within the fields of molecular modeling, structural bioinformatics, and computational biology


amino acid pka chart Arginine is a fundamental amino acid. The glycine, on the side, has no side chain. Cysteine requests are special mentions for one more

www.chem.purdue.edu/courses/chm333/Spring 2013/Lectures/Spring 2013 Lecture 7...

pKa Table for amino acids: * First column (pKa 1) = COOH * Second column (pKa 2) = NH 3 + * Third column (pKa R) = R group H + AMINO ACIDS AS WEAK ACIDS: - Properties of amino acids in proteins and peptides are determined by the R group but also by the charges of the titratable group. Will ultimately affect protein structure.


Acids and Bases: Use of the pK a Table. Discussion: The propensity of a compound to donate a proton is measured as its acid ionization constant, or K a.These K a values cover a wide range of 10 10 for the strongest acids such as sulfuric acid to 10-50 for the weakest acids such as methane. A more convenient scale of acidity is pK a which is the negative logarithm of the K a (pK a = -log K a).