4. The monomers then aggregate to form the amyloid fibrils from any of these states. The mechanism of aggregation of A-beta monomers is thought to proceed through the formation of a high free-energy thermodynamic nucleus of a handful of chains [11], represented here by the hexagonal arrangement of monomers. After the formation of this nucleus, the aggregation proceeds energetically downhill to form the amyloid fibril. The structure of the nucleus and steps between unstructured and amyloid, however, have not been determined.
25. 1. ATP transfers a Phosphate (p) to Amino Acid (AA) 2. Another AA takes the place of P 3. Result: a polypeptide and free P for oxidative phosphorylation in the ATP Cycle.
