Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Towards the mechanism of cell respiration

Researchers at the Institute of Biotechnology of the University of Helsinki have for the first time identified an internal electron transfer reaction that initiates the proton pump mechanism of the respiratory enzyme. These new results are published in the Thursday (April 6th) issue of Nature.

The functions of the lungs, the blood circulation, and the red blood cells in respiration are only an overture to the physicochemical reaction in the cells where oxygen is reduced to water. Oxygen consumption in cell respiration is a strictly controlled enzymatic reaction in the inner mitochondrial membrane. The respiratory enzyme cytochrome oxidase functions as a proton pump that transduces free energy from oxygen reduction to an electrochemical proton gradient, which is utilised by another enzyme to produce ATP, the cells’ general energy currency.

The results by the research group of academy professor Mårten Wikström revealed the coupling between the function of the proton pump and oxygen reduction: an internal electron transfer initiates the first stage of the pump mechanism. "This finding opens the door towards understanding the mechanism, which has been the subject of research for almost 30 years", Wikström says.

The proton pump of cytochrome oxidase is closely linked to the process by which the energy of foodstuffs is transduced into a useful energy source for our cells. Another enzyme makes use of the proton gradient generated by the pump, synthesising adenosine triphosphate (ATP) that powers energy-requiring functions such as muscle contraction and nerve impulses. The central biological importance of this system is evident, for example from the almost immediate death that follows from blocking cell respiration, e.g. by cyanide.

Cytochrome oxidase functions as an energy transducer in much the same way as a fuel cell. It is a biological "nanomachine" that has evolved over billions of years, and has an efficiency better than 90%.

Wikström and his colleagues study both the chemical reaction and the proton pump of cytochrome oxidase by biophysical techniques with a time resolution less than one microsecond. In this way it has been possible to monitor the enzyme’s functions in real time. It takes about one millisecond for the respiratory enzyme to reduce one oxygen molecule to water. This time includes all the partial reactions, and also the efficient energy-transducing mechanism.

Mårten Wikström | EurekAlert!
Further information:

More articles from Life Sciences:

nachricht International team discovers novel Alzheimer's disease risk gene among Icelanders
24.10.2016 | Baylor College of Medicine

nachricht New bacteria groups, and stunning diversity, discovered underground
24.10.2016 | DOE/Lawrence Berkeley National Laboratory

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

New method increases energy density in lithium batteries

24.10.2016 | Power and Electrical Engineering

International team discovers novel Alzheimer's disease risk gene among Icelanders

24.10.2016 | Life Sciences

New bacteria groups, and stunning diversity, discovered underground

24.10.2016 | Life Sciences

More VideoLinks >>>