Room temperature quantum transfer in biological systems

This is not brand new (not this particular research, but quantum systems in nature). It has long been known that some enzymatic reactions take advantage of quantum tunnelling to bridge reaction energies

- sources to come (mobile)

Re: Room temperature quantum transfer in biological systems

#5

Post by dekhn » Fri, Aug 28, 2015, 1:30 PM UTC

robbiep wrote: post #4

This is not brand new (not this particular research, but quantum systems in nature). It has long been known that some enzymatic reactions take advantage of quantum tunnelling to bridge reaction energies - sources to come (mobile)

I'm not sure I've seen reliable examples other than photosynthesis, and it hasn't been "a long time". Happy to inspect your sources.

Re: Room temperature quantum transfer in biological systems

#6

Post by Retric » Fri, Aug 28, 2015, 2:40 PM UTC

dekhn wrote: post #5

robbiep wrote: post #4

This is not brand new (not this particular research, but quantum systems in nature). It has long been known that some enzymatic reactions take advantage of quantum tunnelling to bridge reaction energies - sources to come (mobile)

I'm not sure I've seen reliable examples other than photosynthesis, and it hasn't been "a long time". Happy to inspect your sources.

Depends on what you mean by reliable examples, but it's been researched for well over 25 years. And point where something goes from probably to clear cut gets fuzzy.

(2009) "Quantum biology? Tunneling in enzymes" Over the past two decades the possibility of quantum tunneling of protons in enzymes has attracted considerable attention. (See for example a piece in Nature by Philip Ball (my favourite science writer) or the proceedings of a meeting at the Royal Society

The observed large kinetic isotope effects and their temperature dependence are inconsistent with semi-classical transition state theory,

http://condensedconcepts.blogspot.com/2009/07/quantum-biolog...

PS: This post ended with I align myself with the skeptics, but it's hardly a new idea.

Re: Room temperature quantum transfer in biological systems

#7

Post by rubidium » Fri, Aug 28, 2015, 3:14 PM UTC

robbiep wrote: post #4

This is not brand new (not this particular research, but quantum systems in nature). It has long been known that some enzymatic reactions take advantage of quantum tunnelling to bridge reaction energies - sources to come (mobile)

And the authors of the article acknowledge as much in the intro paragraph with multiple references, what's your point?

I like the authors opening point "Therefore, an important challenge for the growing field of quantum effects in biomolecules is to clearly identify which quantum features with no classical counterpart may manifest in these systems and how they may influence the process of interest."

What's going to be really fun to find is biological systems which naturally exploit efficient quantum processes (tunneling, coherence, or otherwise) to help cells do their thing. This is a nice step on that road.

Re: Room temperature quantum transfer in biological systems

#8

Post by theophrastus » Fri, Aug 28, 2015, 3:19 PM UTC

dekhn wrote: post #5

robbiep wrote: post #4

This is not brand new (not this particular research, but quantum systems in nature). It has long been known that some enzymatic reactions take advantage of quantum tunnelling to bridge reaction energies - sources to come (mobile)

I'm not sure I've seen reliable examples other than photosynthesis, and it hasn't been "a long time". Happy to inspect your sources.

I've been hearing quantum superposition and tunneling as a factor in enzyme mechanisms at least since I was a grad student (circa 1988ish). It was all the rage that perhaps it was the main enzymatic mechanism; but, it grew a little less popular as more 'conventional' explanations seemed to provide acceptable kinetic models. "sources"? too many to list, but just search for quantum effects and enzymes and set your last date to something like 1990ish, like here: https://scholar.google.com/scholar?q=enzyme+mechanism+quantu...

Re: Room temperature quantum transfer in biological systems

#9

Post by dekhn » Fri, Aug 28, 2015, 3:22 PM UTC

Retric wrote: post #6

dekhn wrote: post #5

Earlier quoted context omitted.

I'm not sure I've seen reliable examples other than photosynthesis, and it hasn't been "a long time". Happy to inspect your sources.

Depends on what you mean by reliable examples, but it's been researched for well over 25 years. And point where something goes from probably to clear cut gets fuzzy. (2009) "Quantum biology? Tunneling in enzymes" Over the past two decades the possibility of quantum tunneling of protons in enzymes has attracted considerable attention. (See for example a piece in Nature by Philip Ball (my favourite science writer) or t…

That work is highly speculative (I've studied, but not as my primary work, enzyme kinetics and reaction mechanisms). Finding holes in transition state theory isn't hard and I don't see that it's necessary to invoke tunneling protons to come up with better theories. Even the physical experiments cited in the Ball article, are pretty speculative, and aren't accepted by the mainstream.

I find it pretty amusing, because I proposed tunneling protons in a journal club once, but got laughed down by all the physicists who said "that's silly, proton mass is too high, so probability of proton tunneling is basically zero" (they were being overconfident).

The only real work in this area, which is to say, work that is heavily backed up with data, is the work on quantum mechanisms in photosynthesis: http://newscenter.lbl.gov/2010/05/10/untangling-quantum-enta... This work, since it has a huge amount of high quality experimental work, is considered pretty solid.

Re: Room temperature quantum transfer in biological systems

#10

Post by dekhn » Fri, Aug 28, 2015, 3:24 PM UTC

theophrastus wrote: post #8

dekhn wrote: post #5

Earlier quoted context omitted.

I'm not sure I've seen reliable examples other than photosynthesis, and it hasn't been "a long time". Happy to inspect your sources.

I've been hearing quantum superposition and tunneling as a factor in enzyme mechanisms at least since I was a grad student (circa 1988ish). It was all the rage that perhaps it was the main enzymatic mechanism; but, it grew a little less popular as more 'conventional' explanations seemed to provide acceptable kinetic models. "sources"? too many to list, but just search for quantum effects and enzymes and set your last…

Yes, I think the work that was published in this area was mostly speculative. I want links to mainstream stuff that I can put a little more trust in, like the work done at LBL on photosynthesis and entanglement.