Life At 2 Million Magnification

Molecules are discrete tangible structures with 3-dimensional shapes. They are very small, but at two million magnification they can be modelled and arranged into metabolic pathways basic to life.

Proteins, magnified to this size, vary from simple molecules or monomers approximately 1cm diameter to complex much larger 'machines' made up of 45 or more individual protein chains. They are of various shapes, made of modelling clay and the external chains colour-coded.

Small molecules such as sugars, amino acids, purines and pyrimidines are represented by 'seed beads', colour-coded to the limited extent allowed by relatively few clearly-distinguishable colours. Although the wrong shape and difficult to pack, they have the special advantage of being made into larger molecules such as the coenzymes ATP/ADP and NADH/NAD+ whose representation in biochemical models is of particular importance. Thus ATP is made from the purine adenine (black), sugar ribose (red) and three gold phosphates. ADP is the same, but with two phosphates. NADH is as ADP plus another ribose attached to the end phosphate plus reduced nicotinamide (light blue bead). For NAD+ nicotinamide is a dark blue bead.

Amino acids could also be arranged in linear sequences to form simple protein molecules but this would not convey sensible information, though useful in certain applications, such as depicting the polypeptide chain emerging from a ribosome during protein synthesis. DNA and messenger-RNA may be built up from beads for certain applications, though they are better represented by cords or twine for others. Transfer-RNA is represented by clay models as is the ribosome, a huge molecular machine composed of RNA and proteins.

Production lines

Production Lines: Operons showing messenger-RNA, ribosomes and some ribosomal proteins made on the lines. From E.coli model introductory panel No.10.

Ions are represented by small beads or by glitter. Hydrogen ions appear as very small red fluorescent paper squares. Far too large and thus entirely symbolic these squares well represent proton motive force.

Bead models may be attached to proteins, notably those of bound coenzymes, and other symbolic additions may be made such as iron pyrites particles to represent iron-sulphur clusters or copper wire for copper molecules. Of necessity these must be placed on the protein model surface although their correct placing may be inside it - the important point conveyed however is the possession of given prosthetic groups by particular proteins.

The above smaller components are fixed on to black plastic Foamalux panels with PVA glue, though the larger models incuding ribosomes are best kept separately with their positions marked for assembly at exhibition.

E.coli model
60x40cm models