Energy equation points to cell autonomy

Aug 15, 2014 by Chris Thomas
There is now a strong argument for representing cells as “automata” which means they can move using internally powered methods of locomotion rather than relying on external forces. Credit: Bryan Jones

The mechanical and metabolic energies of cells have been explored through the use of order-of-magnitude estimates, highlighting the energy required for cell shape changes.

A collaboration between California's Teledyne Scientific and Imaging Company and the University of WA, the study compared the required for to execute their motions with the maximum energy available from the cells' metabolism.

Study author Dr Brian Cox says the ratio of these energies can help answer the question of whether cells might be pushed or pulled through their observed motions by forces external to themselves or if they are more likely to move by generating the forces themselves, using their own energy.

"This is important because a cell using its own energy to move can migrate in any direction it likes, depending on how it's defined by its gene expression and what stimuli it might receive," he says.

"Whereas a cell obeying external forces can only move where those forces send it.

"Our estimates of energy are order-of-magnitude estimates, the problem-solving method Enrico Fermi famously used to test whether ideas were feasible and estimate quantities when available data were rough.

"This proved quite satisfactory because the mechanical and metabolic energies turned out to be so different.

"The mechanical energy needed by cells to move is between three and six orders of magnitude less than the available —between 1000 and one million times less."

Dr Cox says given the rate of mechanical energy required per unit time is such a small fraction of available metabolic energy, there is a strong argument for representing cells as "automata".

This means they can move using internally powered methods of locomotion rather than relying on external forces.

"Cells being able to act autonomously is often a necessary condition for successful pattern forming," he says.

"Individual cells must move in directions that lead to local increases in stored mechanical energy, such as moving into spaces already occupied by other cells, to create patterns successfully.

"Our energy estimates also question the assumption that material laws, appropriate for inanimate [lifeless] engineering materials, are also appropriate for describing the mechanics of tissues comprising ."

In fact, the study found that a tissue with cells acting autonomously is fundamentally unlike inanimate material because the cells can draw on their own metabolic energy to re-configure their internal structure.

"In terms of energy, the cells can add new mechanical energy into the system, drawing on their metabolism," Dr Cox says.

Explore further: Wake-up call for more research into cell metabolism

add to favorites email to friend print save as pdf

Related Stories

Wake-up call for more research into cell metabolism

Jul 09, 2014

More scientific research into the metabolism of stromal support cells and immune cells – and the role of the metabolism of these cell types in the development of diseases – could open new therapeutic avenues for diabetes, ...

Towards more efficient solar cells

Aug 13, 2014

A layer of silicon nanocrystals and erbium ions may help solar cells to extract more energy from the ultraviolet (UV, high-energy) part of the solar spectrum. Experimental physicists from the FOM Foundation, ...

How the "biological spark plug" in biomolecular motors works

Aug 04, 2014

Using high-performance computers and quantum mechanical methods, researchers at Heidelberg University have simulated processes that reveal how the "biological spark plug" works in the biomolecular motors of cells. Under the ...

Recommended for you

Devising a way to count proteins as they group

36 minutes ago

A new study from Indiana University-Purdue University Indianapolis and University of California Berkeley researchers reports on an innovative theoretical methodology to solve "the counting problem," which is key to understanding ...

Mysteries of 'molecular machines' revealed

1 hour ago

"Inside each cell in our bodies and inside every bacterium and virus are tiny but complex protein molecules that synthesize chemicals, replicate genetic material, turn each other on and off, and transport ...

Bacteria are wishing you a Merry Xmas

7 hours ago

A bacterium has been used to wish people a Merry Xmas. Grown by Dr Munehiro Asally, an Assistant Professor at the University of Warwick, the letters used to spell MERRY XMAS are made of Bacillus subtilis, ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.