1. Basicity of some amines AmineKbpKb Ammonia NH 3 1.80E-054.74 Propylamine CH 3 CH 2 CH 2 NH 2 4.70E-043.33 2-Propylamine (CH 3 ) 2 CHNH 2 3.40E-043.47 Methylamine CH 3 NH 2 4.40E-043.36 Dimethylamine (CH 3 ) 2 NH5.40E-043.27 Trimethylamine (CH 3 ) 3 N5.90E-054.23 Aniline C 6 H 5 NH 2 3.80E-109.42 4-Methylaniline 4-CH 3 C 6 H 4 NH 2 1.20E-098.92 2-Nitroaniline1.50E-1514.82 3-Nitroaniline2.80E-1312.55 4-Nitroaniline9.50E-1413.02 2 B + H 2 O HB + + OH - K b = a(HB + ) x a((OH - )/[a(B) x a(H 2 O)]

2. The 21 amino acids found in eukaryotes. (Grouped according to their side-chains' pKa values and charge at physiological pH 7.4)

3. The peptide bond

4. Polymerisation of ε-caprolactam to a polyamide (Nylon-6) O H2OH2O  -Aminocapronsäure

6. a -helix

7. Primary structure: Amino acid sequence in a polypeptide (protein) amino acids

8. 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.

9. 3D structure of the protein myoglobin showing colored alpha helices. heme prosthetic group, co-factor

10. Beta-meander motif Portion of outer surface Protein A of Borrelia burgdorferi complexed with a murine monoclonal antibody. Psi-loop motif Portion of Carboxypeptidase A.

11. Die vier Ebenen der Proteinstruktur, von links nach rechts: Primärstruktur, Sekundärstruktur (β-Faltblatt unten, α-Helix oben), Tertiär- und Quartärstruktur. a -helix  -sheet primarysecondarytertiaryquaternary structure

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

13. 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)