Post on 17-Jan-2016
The Amazingly Fantastic BZ Oscillating Soup
And its Connections to Life, the Universe and More
Boris Belousov 1893-1970
Discovered and investigated the reaction ~ 1952
Had difficulty in publication
Anatol Zhabotinsky 1938-2008
Investigated the reaction further1960’s
Now called
The Belousov – Zhabotinski Oscillating Reaction
or B-Z
B-Z Components
Sulfuric Acid
Potassium Bromate
Cerium (IV) Sulfate (catalyst)
Malonic Acid
Ferroin (indicator and catalyst)
B-Z mechanism 1969
Five basic steps, each thermodynamically possible, explained how B-Z reaction
worked.
B-Z Oscillations
Necessary Conditions:
Non-linear reactions
Positive Feedback
Negative Feedback
Time delay between reactions
B-Z Connections
The Bray-Liebhafsky Oscillating Reaction
1918
Acid, potassium iodate,
hydrogen peroxide
B-Z Connections
The Briggs-Rauscher Oscillating Reaction
1972
Acid, malonic acid, catalyst,
potassium iodate, hydrogen peroxide
B-Z Connections
Many more chemical oscillators in CSTRs
(Continuously Stirred Tank Reactors)
Flow reactor
B-Z Connections
Hundreds more oscillators discovered
B-Z Connections
Mathematical Techniques
COmplex PAthway SImulator
COPASI
Uses differential equations
Differential equations
Rate is proportional to concentrations to some power
dx/dt = -k xm yn
Computer can calculate x and y at any time
B-Z Applications
Chemical Control of Rhythms
B-Z Connections
Biological Oscillators
Biological Rhythms
Time Scale Biological Rhythms
Time Scale
Neural rhythms
0.001 s to 10 s Ovarian cycle 28 days (human)
Cardiac rhythm
1 s Annual rhythms 1 year
Calcium oscillations
Seconds to minutes
Biochemical oscillations
30 s to 20 min Rhythms in ecology and epidemiology
years
Mitotic oscillator
10 min to 24 h
Hormonal rhythms
10 min to 3 – 5 h (24 h)
Circadian Rhythms
Chemical Control of Rhythms
B-Z Target Waves
Tidal Map
B-Z Connections
Structure from Homogeneity
Ilya Prigogine received Nobel Prize in 1977 for work on irreversible thermodynamics
(far from equilibrium)
Far from equilibrium,
energy may be converted into structure.
Implications for development of patterns
and for development of life on Earth
B-Z Applications
Slime mold patterns
Slime Mold
Slime Mold
Slime Moldgrowing in Petri dish
Slugs form, ~ 25 secondsStalks form, ~ 35 seconds
BZ target waves
B-Z spiral waves
Watch what happens to waves when cut at 11 and 13 seconds;
(spiral waves form)
B-Z Connections
Geology
B-Z Connections
Geology
B-Z Connections
Structure from Homogeneity
Turing Patterns
Turing Patterns
Alan Turing, British mathematician
1912-1954
Alan Turing, best known for breaking the German enigma code in WWII.
Also envisioned computers that could have code in memory and be programmed for
many tasks
Known as Father of Artificial Intelligence
Turing Patterns
“The Chemical Basis for Morphogenesis”
Developed a theory of combined reaction – diffusion which predicted oscillatory chemical
reactions and pattern formation (1952).
Patterns now called Turing patterns.
First realized experimentally in 1990s
B-Z Connections
Structure from Homogeneity
Turing Patterns
B-Z Connections
Structure from Homogeneity
Turing Patterns
B-Z Connections
Structure from Homogeneity
Turing Patterns
Not only visual patterns, but also morphogenesis
the development of body shapes and limbs.
Caused by diffusional waves of molecules across developing stem cells
Caused by diffusional waves of molecules across developing stem cells
2014: Confirmation of Turing’s theory
Using microdroplets of the B-Z reaction
dispersed in oil;
representing individual cells
Structure from Homogeneity
Turing Patterns
B-Z Connections
Coupled Oscillators
B-Z Connections
Coupled Oscillators
Human organs
Suprachiasmatic nucleus (SCN)Master clock
B-Z Connections
Excitable media
Nerve transmission
Heart rhythms
B-Z Connections
Spiral waves
Scroll waves
Heart rhythms
Scroll waves
B-Z Target Waves
Heart Arrhythmias
scroll down to Figures 13, 14, 15, 16
Heart Rhythms
choose from :”Select a condition”below beating heart
B-Z Connections
Weather
Orbital Diagram
B-Z Connections
Route to Chaos
Orbital Diagram
B-Z Connections
Cosmology?
Spiral galaxy
Spiral galaxy
That's All, Folks
B-Z Connections
Coupled Oscillators
B-Z Connections
Coupled Oscillators
B-Z Core reactions Process A2
5Br- + BrO
3
- + 6H+ → Br2 + H2O A1
3(Br2 + CH2(COOH)2 → BrCH
2(COOH)2 + Br
- + H
+) A2
Net Process A1 +Process A2
2Br- + BrO
3
- + 3CH
2(COOH)2 + 3H+ →
3 BrCH2(COOH)2 + 3H2O
B-Z Core reactions Process B
HBrO2 + BrO3
- + H+ → 2BrO2
. + H2O
2(BrO2. + Ce(III) + H
+ → Ce(IV) + HBrO2)
HBrO2 + BrO3
- + 2Ce(III) + 3H+ →
2Ce(IV) + 2HBrO2 + H2O
HBrO2 + HBrO2 → HOBr + H+
+ BrO3
-
B-Z Core reactions
Net Process B
BrO3
- + 4Ce(III) + 5H+ →
4Ce(IV) + 2HOBr + 2H2O
B-Z Core reactions
Net (unbalanced) Process C
BrCH2(COOH)2 + BrO
3
- + Ce(IV) + HOBr →
Ce(III) + Br- + H2O + CO2
B-Z Core reactions
A bromate + bromide + MA → BrMA
B bromate + Ce(III) → HOBr + Ce(IV)
C Ce(IV) + BrMA → Br- + Ce(III) + CO2