Self-Assembly Flashcards
What are the seven classes of self-assembly?
Strict
Irreversible
Precursor modification followed by self assembly
Self-assembly with post modification
Assisted
Directed
Self-Assembly with intermittent processing
What is strict self-assembly?
Entirely spontaneous
Completely reversible
Represents the thermodynamic minimum of the system
What is irreversible self assembly?
Product formed through a series of irreversible (covalent) bond forming steps
Under kinetic control
No self-correction
What is kinetic control?
Faster reaction
Lower energy transition state
What does the tobacco mosaic virus consist of?
RNA and 2130 protein subunits which assemble around the strand to form the virus superstructure
When is protein folding strict and directed?
Strict - without chaperones or prions
Directed - with
Explain the biosynthesis of collagen
Collagen forms long fibrous bundles outside the cell.
To prevent fatal formation within cells, the collagen precursor has end capping amino acid chains.
These are removed by enzymes after the procollagen is secreted
How is insulin synthesised?
Preproinsulin. Cysteine bond form to make proinsulin, then the chains are removed to form insulin
Why are transition metals excellent templates for directed self-assembly?
1) Metal ligand coordinate bonds are thermodynamically strong, and possess varying degrees of lability
2) TM ions often have very specific geometric requirements because of ligand field effects
What is the Jahn-Teller Effect?
Distortion of geometry due to elongation of bonds
How many copper atoms can helicates have?
Up to five
When can helices form?
When two strands of the same length form
What is helicate formation an example of?
Strict self-assembly
Why do racks and ladders form?
Thermodynamic driving force results in the formation of strict oligomers
Why are hydrogen bonds suitable for directed-strict self assembly?
They are directional
