Table of Contents
What are the 20 structure of amino acid?
Molecular and linear formulas
Amino acid | Abbreviations | Linear formula |
---|---|---|
Arginine | Arg | HN=C(NH2)-NH-(CH2)3-CH(NH2)-COOH |
Asparagine | Asn | H2N-CO-CH2-CH(NH2)-COOH |
Aspartic acid | Asp | HOOC-CH2-CH(NH2)-COOH |
Cysteine | Cys | HS-CH2-CH(NH2)-COOH |
Which amino acid has three pKa’s?
Glutamic acid
Amino acid | pKa1 | pKa3 |
---|---|---|
Glutamic acid | 2.19 | 4.25 |
Lysine | 2.18 | 10.53 |
Arginine | 2.17 | 12.48 |
Histidine | 1.82 | 6.00 |
How are the 20 amino acids different from each other?
There are 20 amino acids that make up proteins and all have the same basic structure, differing only in the R-group or side chain they have. They can be subdivided according to their properties, dictated by the functional groups they possess. Broadly they are divided by charge, hydrophobicity and polarity.
How many different kinds of amino acids are in our bodies?
20 amino acids
Roughly 500 amino acids have been identified in nature, but just 20 amino acids make up the proteins found in the human body.
What is the most polar amino acid?
‘Polarity’
Amino acid | Abbreviations | |
---|---|---|
Alanine | Ala | nonpolar (2) |
Arginine | Arg | polar (1) |
Asparagine | Asn | polar (1) |
Aspartic acid | Asp | polar (1) |
What are three properties used to classify amino acids?
Nonpolar, polar, and electrically charged are the three properties of side chains used to classify amino acids.
Which is not present in a pKa amino acid?
not present Amino acid 3-letter code 1-letter code pKa Cα-COOH pKa side chain Alanine Ala 2.34 2.34 6.02 Arginine Arg R 2.17 R 2.17 12.48 Asparagine Asn N 2.02 N 2.02 5.41 Aspartic acid Asp D 2.09 D 2.09 3.86
What are the values of pKa1 and Pi?
Amino acid pKa1 pKa2 pI Glutamine 2.17 9.13 5.65 Serine 2.21 9.15 5.68 Threonine 2.09 9.10 5.60 Tyrosine 2.20 9.11 5.66
Which is the first column in the pKa table?
pKa Table for amino acids: * First column (pKa 1) = COOH * Second column (pKa 2) = NH
Which is the first amino acid to deprotonate?
α-COOH (pKa = 2.3) comes off first (has lower pKa) α-NH3+ (pKa = 9.9) Others come off SEQUENTIALLY in ascending order of pKa. 2. Write out structures for sequential deprotonation and place pKa values over the equilibrium arrows.