What is bioinorganic chemistry?
the study of inorganic elements in biology
bioinorganic applications
- catalysis
- signalling
- regulation
- sensing
- defence
- structural support
all organisms depend on..?
metalloenzymes or metal contain enzymes, this is due to organic proteins and their side chains not being able to
- activate small molecules, H2, N2, CH4 and CO -essential for life
- hydrolyse (effectively) many compounds eg. peptides, phosphates and urea
how are metalloenzymes optimised?
- the metal ion sites in metalloenzymes are optimized for
- selective uptake
- catalytic activity
Biomimetic relation
- many things nature can do more efficiently and selectively that we are synthetically able to do
study of bioinorganics, aids research into
- Energy: collection, conversion and storage
- Catalytic activation: of inert compounds in mild cond.
- Synthesis: efficient selective synthesis of high value substances
- Detoxification: of chemical compounds or elements
abundance relation
There is a loose relationship between abundance of elements in the universe and abundance of elements in organisms on earth
What is a dose-response diagram?
PICTURE
An organism’s diet must contain the correct amount of all the esesential elements.
the essential element concentration for optimal health within any given organism can be represented by a dose-response diagram
Dose-response: axis
physiological response (positive @top, negative @ bottom) concentration/ dose along bottom
name naturally occuring ligands
- Water H2O
- O2- and OH-
- inorganic suphide S(2-)
- phosphates XPO3(2-)
- bioligands
What are the three most important bioligands?
- Proteins
- Nucleic acids
- Macrocyclic chelate ligands
Bioligand 1: Proteins
c
Bioligand 2: Macrocyclic ligands
- tetrapyrrole macrocycles are v well studied bioligands.
- they are referred to as prosthetic groups
- additional non-amino acid components of proteins
- All tetrapyrroles are tetradentate and at least partially unsaturated
- In deprotonated state, they are able to bind to specific metals very strongly (4xN-M bonds can form)
Macrocyclic ligands: examples and features
Features:-Planar or close to planar
- Aromatic (18 pi electrons)
- Often form intensely coloured compounds
Examples, porphyrin, chlorin, corrin
PICTURE
Bioligand 3: Nucleic Acids
- Constructed from nucleotide segments (phosphate groups, sugars, nucleobases ( eg. A, C, G, T)
- EG. ATP, DNA and RNA
Potential donor sites for binding to metals:
1- O atom on phosphate group
2. OH groups on sugar
3. N or O atoms from nucleobase
what is the HSAB
Hard-Soft Acid-Base theroem
