Basicity of some amines

Amine Kb pKbAmmonia NH3 1.80E-05 4.74

Propylamine CH3CH2CH2NH2 4.70E-04 3.33

2-Propylamine (CH3) 2CHNH2 3.40E-04 3.47

Methylamine CH3NH2 4.40E-04 3.36

Dimethylamine (CH3) 2NH 5.40E-04 3.27

Trimethylamine (CH3) 3N 5.90E-05 4.23

Aniline C6H5NH2 3.80E-10 9.42

4-Methylaniline 4-CH3C6H4NH2 1.20E-09 8.92

2-Nitroaniline 1.50E-15 14.82

3-Nitroaniline 2.80E-13 12.55

4-Nitroaniline 9.50E-14 13.02

2

B + H2O HB+ + OH- Kb = a(HB+) x a((OH-)/[a(B) x a(H2O)]

The 21 amino acids found in eukaryotes.

(Grouped according to their side-chains' pKa values and charge at physiological pH 7.4)

The peptide bond

Polymerisation of ε-caprolactam to a polyamide (Nylon-6)

O

H2O

-Aminocapronsäure

CH

CHN

O

N

CH2

SH

O

CH

CH2

CHN

O

N

OCH2

OH

H

H H

H

a-helix

Primary structure: Amino acid sequence in a polypeptide (protein)

amino acids

CH

CHNH

O

NH

CH2

SH

O

OHCH

CH2

CHNH

O

NH

OCH2

OH

Hemoglobin (English pronunciation: /hiːməˈgloʊbɪn/; also spelled haemoglobin and abbreviated Hb or Hgb) is the iron-containing oxygen-transport metalloprotein in the red blood cells of all vertebrates.

3D structure of the protein myoglobin showing colored alpha helices.

hemeprosthetic group, co-factor

Beta-meander motifPortion of outer surface Protein A of Borrelia burgdorferi complexed with a murine monoclonal antibody.

Psi-loop motifPortion of Carboxypeptidase A.

Die vier Ebenen der Proteinstruktur, von links nach rechts: Primärstruktur, Sekundärstruktur (β-Faltblatt unten, α-Helix oben), Tertiär- und Quartärstruktur.

a-helix-sheet

primary secondary tertiary quaternary

structure

The crystal structure of the chaperonin. Chaperonins assist protein folding.

Three possible representations of the three-dimensional structure of the protein triose phosphate isomerase. Left: all-atom representation colored by atom type. Middle: Simplified representation illustrating the backbone conformation, colored by secondary structure. Right: Solvent-accessible surface representation colored by residue type (acidic residues red, basic residues blue, polar residues green, nonpolar residues white)